Yeah. 😃
In a previous life, I used to work on this stuff for a couple large conglomerates, and it was mostly about being able to justify the space it would take in the user interface. There were a few things we'd examine like if we thought enough people would use it, if the brand/logo aligns with our values, if there was a potential for a joint GTM and what would that look like, etc. We actually kinda were the gatekeepers, so we were on the other side of the equation. 🤣
For newer/smaller/emerging businesses (which is where I'm at right now, albeit, different capacity), yeah all those things you mentioned are certainly important, but by far the most important thing is distribution. If people aren't able to discover the app and access it frictionlessly, then everything else is moot. 😃
Now of course, you could do both (for the most part) work with the gatekeepers and also try to reap the benefits of what you described...you need to be convinced the user base will be sufficiently large enough to be worth the squeeze, otherwise it could be potential noise/detract from the user experience.
I do think decentralized/portable identities will be ubiquitous in the future...just not sure who the major players are going to be, which is why I kind of participate in a lot of them all at once right now (Nostr, Bluesky, Farcaster, lens, Mastodon). Trying to keep tabs and being agnostic about it.