I wished bitwarden would not need a backend and for sure not one tied to the windows and .net ecosystem.

I would be willing to pay (even subscription) for a nice set of UI clients (android, iOs, mac, Linux, Windows), plugins (Chrome, Firefox) that can just work with an encrypted file on ANY cloud or p2p file sync solution (i.e. resilio sync).

Unfortunately there seems not to be such a thing that is open source and does not want to lock you in to their infrastructure and services.