The problem with section 3 is that it says nothing of running for a position, just that someone who has engaged in insurrection or rebellion may not hold an office, elected or appointed. If we go with the strictest interpretation, Trump absolutely can run for president. He can even win. However, can he hold the office? That's another question. It could be sidestepped if the Republicans gain 2/3rds majority in both Houses of Congress as they can "remove such disability." If they don't, it will go to the Supreme Court most likely. And, well, barring several of them dropping dead or retiring, we all know how that is gonna play out(2000 all over again, basically).
What we really need to see in 2024 are states amending their constitutions to bar those who engage in insurrection and rebellion from being on the ballot or, better yet, from being certified or whatever it is in each state when deciding electors for the electorate college vote. This is something that should have happened after Jan 6th, but, well, here we are.
Regardless of what happens, any outcome other then Trump being made sitting president again is going to harm the Republicans going forward as it will further alienate Republican voters from the voting process. The likely violent backlash from a Trump loss will also likely alienate more levelheaded independents from voting for Republicans, as well. If he is refused to be seated, shit is going to be insane. This election is a hail Mary for the Republicans - if it goes any other way than in their favor they have likely hamstrung themselves for the foreseeable future. It could even blow up in their faces if it goes to them if Trump actually goes through with trying to make his senile self a dictator.