the most honest reason I read about is probably that former Twitter user who felt out of place on Mastodon or other Activitypub servers because the “Nerds” who care about privacy and decentral systems which were already on it have a different microblogging culture and they didn’t want adept

so now a new competitor gets traction because the people who felt out of place on Mastodon can relife the Twitter experience from over a decade ago
the fake exclusivity even make you feel special despite the lack of features

Some podcasts have contracts to be Spotify exclusive (they get a compensation for it)

additionally you don’t need to jump across several hops to flash custom roms on Pixel phones (or tablets)
it’s easy as using a web browser

meanwhile custom roms on Xiaomi or Samsung are a huge pita to setup and require almost shady looking korean or chinese (windows) applications

the listed ones have contracts with publisher to get legit keys where the developer gets it share too