I feel more people should point out how incredibly awful American elections are. They're almost astonishing! No wonder you have to rely on the media guessing the winner weeks or even months before the winner is actually officially determined (whereas in most countries, "calling" is basically only of interest to news channels to give them something to talk about for ten minutes before the official result).
1. you have an election. The rules for this vary with the state, in some cases even with the county. In some states, the election actually lasts for weeks, or even months. The rules for the election are decided by a combination of federal rules, state rules, the whim of local officiators, and arbitrary interjections by state and federal courts. The rules can change at any time, even once the election has already started, and some details (eg about counting and 'curing' of postal votes) apparently may not even be decided until after the election has finished. And weirdly, there's a tradition that you have to queue to vote, for hours and hours or in some places even all day.
[oh, and you insist on voting in alarmingly unsafe ways. Postal voting is known to be susceptible to fraud and disenfranchisement, so having the entire population vote by post as happens in some states just seems insane. Even worse, voting in person in America usually means using a voting machine - these have had a catalogue of serious faults, can in some cases be hacked electronically, and generally cannot be fully audited, as they operate in a way that is considered a 'commercial secret'. In some states, the machines and their black-box methodologies are the only record of votes, as there are no paper ballot copies; in others there is a paper copy, but it's generated by the machine itself. Now, to be clear, it would be very hard to throw an entire Presidential election. But individual races could be, and have been, decided by fraud, and choosing intentionally the least secure methods possible is just opening yourself up not only to fraud but to the fear and perception of fraud!]
2. you count the votes. Now, in the rest of the world, this is done overnight, with perhaps one or two contentious recounts taking a day or two extra. But in America, it takes days. And then weeks. And then months! We're now almost a month after the 2020 election, and you still haven't even finished counting the votes! [four congressional seats are still being counted; Biden was 'called' as President when there were still half a dozen states that hadn't finished counting]
3. then the candidates can buy recounts. The rules vary with the state. This seems to be a money-making scheme of some kind, since you can buy recounts even when you have absolutely zero chance of the recount changing the result. Then again, some states have automatic recounts even when there's zero chance of changing the result. [statewide recounts never change the result by more than a few tens or a few hundreds of votes... but you still have them even when the margin is tens or hundreds of thousands of votes. Why!?]
4. then the results have to be certified by political party appointees in each individual county. This takes weeks, for some reason, even though it's not clear what process these appointees are meant to go through other than reading the results. [for context, the UK process is: you count the votes in a big room; the results are handed to a generally non-partisan person who stands at one end of the room with a microphone, and reads out the results. Done.]
5. then the certified results have to be certified AGAIN by political appointees at the state level. For some reason. This also takes weeks. [so that now, a month later, states are still certifying results even for the presidential election, let alone the closer or less important races]
6. then the legislature of each state must decide whether to accept the results, or to ignore them and decide their own results. This hasn't happened for a while, but remains a live option, particularly if the first five steps have taken too long (it was seriously planned in Florida in 2000, before the Supreme Court stepped in to overrule the voters directly).
7. then the results must be "ascertained" by the Governor of each state. They must do this in nonuplicate. Is nonuplicate the right word? I don't know, because other than the US electoral system nobody ever needs that word! Each copy must match.
8. then, more than a month after the election, the first phase of the election finally ends. All the voting so far has just been to select electors, who then gather together. They must then all certify in sextuplicate the certificate of the ascertainment of the certification of the certification of the votes. They then... start voting on their own officiating officials to officiate their votes. Eventually, they actually vote. In some places, they can decide on the spur of the moment who to vote for. In others, they can do this but will be punished if they defy the popular vote. In others, they are required to pledge not to defy the popular vote - in some places they can be rejected for refusing to pledge, in others they can't be - but their vote still counts. In other places, state laws purport to prevent them from defying the popular vote. All these rules vary from state to state, and all are subject to continual judicial interpretations and overrides at the state, circuit and supreme court level. [we haven't even talked about the real first stage of the election, which is nominating these 'slates' of the electors to be voted upon, and what happens if a nominated elector is subsequently prohibited or otherwise unable to vote, which is its own huge issue....]
9. after the electors have voted, they must unanimously certify their own votes. It's unclear what would happen if an elector refused to go along at this stage. They must then produce a paper copy of this certification - in sextuplicate. Again, each copy must match exactly, or else they can be called back to start again.
10. then you wait around for a month.
11. then the new federal House and Senate meet, presided over by the outgoing Vice-President (who may be a candidate for Vice-President in the election, or even a candidate for President!). Both houses then certify the certificate of votes, and the certificate of ascertainment of electors. It's not clear how they do this, or what happens if they don't. But if even a single Representative and Senator agree to challenge the vote of even one state, there has to be a full debate on that state. There are some laws around this stage, but they're probably unconstitutional. Unfortunately, since America operates on a "have a go and see what happens!" approach to legal matters, nobody ever knows what rules they should have followed until it's too late to follow them... anyway, hopefully at this state Congress is able to agree to make one candidate the President-Elect.
12. then, assuming that Congress has been able to decide on a new President-Elect - and there's a whole load of complicated and ambiguous alternative arrangements if they haven't been - you wait around a bit more, until the President-Elect becomes the President more than two and a half months after the original election. Assuming they haven't died in the meantime!
This system, with respect, is nuts.