Like you said, it's almost impossible to be productive in Congress unless you caucus with one of the parties to get put on good committees. But if you can start winning seats in city councils and state legislatures and then build up to statewide offices then you can grow from there. The issue is, those are inverse problems. All the money will come in if you're chasing national level positions where all you can do is play spoiler, but all the power comes from the small elections that grow the party. You're only nationally relevant once you can win statewide somewhere, because then you can elect a Senator or collect electoral college votes. If you can win a governorship somewhere, that person can run for Senate down the road and have a fighting chance.
[Post edited by CMUHoo at 07/28/2022 1:46PM]