And I believe (not totally sure though) that IP is always part of the bankruptcy assets so probably insolvent companies are not even allowed to just open-source their stuff and allow configuration of the backend so users could set up community-servers and keep things running.
Completely different are cases where companies continue to live but lock features behind new paywalls like Happiest Baby with their Snoo bassinet, invent fees to hinder re-sale like Peloton or cripple working hardware like Sonos did.
Those make me unreasonably mad, not just because I already have too many subscriptions for things that improve my QoL but add up, but also because I do care about my CO2 and environmental footprint. I do not want to trash working devices just because they are now 2 years old. Companies should untether them if they think further cloud support is no longer viable and at the very least should support them for 7-10y.