I think a competent opposition party would be great for the US. But regardless of the candidate, US voters had three clear choices in the 2024 Presidential election: (1) I support what Trump is going to do, (2) I am fine with what Trump is going to do (abstain/third-party), (3) Kamala Harris. I think it’s extremely clear 3 was the best choice, but it was the least popular of the three.
Was that less bad than what Trump has done in one year? Yes. But Trump in his first term was less bad than this, and recency bias means that what we didn't like about Biden was more prominent in our minds.
But my option 4 looks just like your option 2 in terms of how people voted. I'm just saying that the motive may have been different.
Democracy is a healthy process - I don't know why we buy the stupid line of "we need party unity" when what we need is an efficient expression of the voters will and having that expression is what best forms unity. There are some old Hillary quotes that make me absolutely rabid.
It's really a problem of money though. The DNC really are the king makers when it comes to candidates. That and PAC money are the requirements to get a nomination. At least when it comes to presidency. Smaller elections you get more freedom to have a successful without such things. The whole system needs an overhaul unfortunately and I don't see any candidate from any party looking to fix that any time soon.
That's only problem in the USA. Other western democracies are able to have snap elections done in two months.
The first couple states really end up determining who usually wins the nomination and financial backing. It takes time to move a candidate between places and set up multiple events and fundraisers. Now in state and city elections the US can do those quickly as well. Smaller area to cover and campaign and the community stays informed. It doesn't help that national elections involve institutions like the electoral college instead of a popular vote. That's a different problem though.