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?

You're right that it's just a new label on decentralized resource allocation networks that have been around for awhile. They bootstrap supply using cryptoeconomic incentives, and then open marketplace competition drives down price. Livepeer has grown to transcode over 3,000,000 minutes of video/week for 100's of apps.