If you find the project suspicious and their claims is quite not possible then its good to have doubts on them since taking extra precaution on things you don't trust is a way for you not to get scam if their intention is to deceive people.
For now I will not trust project who claims about they can mine on phone or they can do that thing you say because those people who says to good to be true is shady people.
I guess you didn't even carefully study even one of them. TAU for one is already doing their mobile mining thing. Minima's about to be released. I don't know about Minima but TAU has its own chain. As I've somehow mentioned, a tech team should consider block size and capacity to fully operate on mobile for mining. It need not be any POS or POW consensus as such consumes too much. It could really drain.
What I find interesting is that when Pi started doing their KYC thing, I already had doubts. If these two projects asked for another kyc before withdrawal, then it's a sure thing that they aren't decentralized and might pose a risk in the future.
Three problems must be solved:
a. decentralization
b. security
c. speed
Mobile mining tech has yet to move in the industry but it could prove to be a great thing in the future. That's what I tought.