connect this with shit pulled out the trash does no’t help us influence others.
…okay? One of the OP’s suggested points is literally
bring an old device back to life with Open Source software
And I would not do my first Linux installation on my main computer anyway. Except as dualboot, that would work for anyone who has the device and space. Or on a non-upgradeable device when Windows10 security updates end in October, but I guess those are “trash computers”.
On Android, not sure if iOS has something similar. Install Shelter from F-droid to create a work profile and control whether the apps in work profile are active or not, install WhatsApp, Facebook etc. in the work profile, disable work profile. That way launching the app becomes a 2+ click process (enable work profile, launch app) that registers and can’t be done out of habit. Plus it adds some granular control to your systen, you could disable location, have a shorter/no contact list, or stricter VPN/NetGuard rules for the apps in the work profile so they have more limited access to track you.