What are the "DePIN" projects that people think are most likely to actually work?

It feels like the category is a new name for something that's been around for a decade (StorJ, various decentralized ubers...) but has never gotten off the ground? So what's the bull case for why it will get off the ground now?

Telco, that's new.

The bull case: we're finally at a stage where blockchains are not just  software projects, but connecting to hardware to provide real services that we ALL use.

That's how we generate revenue that isn't tied to the whim of speculators.

I'd invite you to check out World Mobile.