Hot take: Trump isn't competitive against Biden unless there some sort of upset. Even if the economy stutters along where it is now, Biden wins 55-45. Independent voters don't really like Biden much, and various groups have their bones to pick with either him or the Democratic Party, but no-one who isn't a Trump cultist or willing fellow-traveler will vote for Trump again.
Idk if it'll be 55-45 but I tend to agree; even in most of these potentially flawed polls, it seems the "undecides" tend to be very favorable for Biden. And yeah, there are very few people who are going to flip either way; the biggest danger is probably Trump just activating even more voters than 2020.
I was too casual with 55-45. I suspect it would be closer to Biden 53%, Trump 45% nationally, but still a far more solid win than 2020. Unless non-Trump voters get complacement, or there is some sort of upheaval that impacts the race. I have a hard time seeing Trump find any significant number of new voters. The bigger danger will be a 2016 replay, where Biden is seens as "having it in the bag" and just enough people blow off voting, or vote third party to hand a win to Donald. But I have a hard time seeing that, either.
Now, I do expect something to change, maybe a lot of things. (Among others, I do not think Trump is certain to be coronated as the nominee.)
after 2016 I don't think anyone will see any election as being in the bag. Turnout has been high in every election since then.