You can self-host, but it's a monthly subscription instead of a perpetual license.

Is there any proof that "self hosted" is still working, wouldn't surprise me if at least part of it relies on centralised services.

In a sane world the CTOs choosing this would be held accountable. The massive global economic fragility which is created by the centralisation of society is a massive risk. Diversity is important, we see it time and time again how optimisation causes panic, from crowdstrike to microsoft. When your outsourced provider is "too big to fail", you have a problem that government needs to deal with.