Even if state and local elections are ranked choice, the presidential election will still be a first past the post election and the electoral college is still designed for a two party system.
My city had ranked choice voting implemented by Democrats in the 1970s. They elected the first black mayor, who is still one of our most beloved mayors in the city's history, under RCV.
Then Republicans made it illegal at a state level when they had a trifecta. Democrats keep introducing bills at the state level to allow RCV, and Republicans take more and more drastic action against it. So yeah... I want more Democrats in my state government so we can have RCV.
The Dems will preserve a political model that's at least malleable. 3rds will need to work together to push ranked choice more and more into voters' field of view.
Republicans will swan-dive into fascism, in which case 3rds (and everyone else) are fucked.
Dems aren't going to help 3rds directly, but any one who wants the possibility of a 3rd party victory later is committing political suicide by failing to vote blue as a means of buying time. Voting 3rd when that 3rd has no potential for victory is self-destructive.
Some will at small, minor levels, but never enough to cause a serious threat. It's like how it's socially permissible and legal to make worker co-operatives and the like, the fact that it's non-threatening to the status quo keeps it a useful carrot that will never arrive at a scale that causes drastic change.
Linkerbean: usual concern trolling and anti-democrat talking points
Me: You're just a republican troll trying to get left leaning folk to not vote for democrats
Linkerbean (and I quote exactly): Cope.
Me: ...
Linkerbean: <deletes comment>