What will keep alt coins alive in crypto winter?

On a surface level I understand why they fail- FUD runs rampant and everyone pulls out with no new money coming in to float it.

I guess my understanding of crypto life/death in general is just limited. Have any crypto’s come back from the dead? Are they slow deaths by getting delisted one by one? Is hype/community the only thing that keeps a crypto alive through the winter?

Is this another question that’s simply answered with “nobody know bro stop asking”, or are there specific measures projects can take to fight a good fight and stay alive?