Maybe once it matures a bit I'll deploy E2EE, but i gather it's a bunch of work.
I ended up finding some possibilities out there that could potentially help me build stuff. One of them is RxDB [1], which offers WebRTC syncing - you'd still need a signaling server, I suppose, but all sensitive information could be synced E2E-encrypted via WebRTC.
Then there's CRDT's [2], which is a universe that turned out to have multiple possibilities that match (at least partially) my needs. In particular, the next thing I want to take a look at is cr-sqlite [3], which might be just thing I needed to kick-off some side-projects.
I'm posting here cause I just found some hope of not needing to build a traditional client-server app and having to deal with all the hassle involved in securing a server (and with fear that my efforts could be not good enough), and I thought someone else could benefit from getting to know these things.
[1] https://rxdb.info/ [2] https://crdt.tech/ [3] https://github.com/vlcn-io/cr-sqlite