Ignoring that IQ is a grift and a lie: Sitting within a standard deviation of average intelligence is NOT a bad thing. If intelligence really could be measured it would mean you’re capable of doing anything about as well as anyone else.

It’s simply trust in the organization that maintains the app.

Unless you’re coordination/organizing about legal grey or red areas then it’s not much danger. Meta says it’s E2E but do they really not have access to your data? I don’t believe them. Any data they have would be happily handed over to the authorities just like your protonmail.

Signal just straight up doesn’t have access since it’s all stored at the endpoint and they provide no remote backup.

Yes but if taxes are paying for the system then preventing tax exemption and building a competitive standard of care system heavily disincentivizes use of the private system.