And the Electron desktop apps are far too bloated.
No argument. Electron is categorically silly in its own right, lol.
They don’t want you installing it from a safer space like F-Droid.
F-Droid is by no means safe; use Droidify.
They still by default send notification metadata to Google & Apple (websocket support exists but drains a fair amount of battery & they refuse to support UnifiedPush).
Easy: use the FOSS version of Molly instead of the default Signal app.