Just don't "upgrade" and ignore all the propaganda telling you bad things about that. Keep building apps that work on older, less-hostile devices and spread the word to oppose this very deliberate planned obsolescence.
Also easily remotely ownable, so you can be spied on without even having to install any software at all. And any that aren't now will be a couple of years after they fall out of support. Which, by the way, is very hard for the community to step in and do, since they're full of undocumented proprietary binary blobs.
> Just don't "upgrade" and ignore all the propaganda telling you bad things about that.
... and when your fully owned device finally breaks completely?
There's a whole community keeping these devices alive, I trust them far more than Big G.
via a crafted HTML page
Don't forget that the majority if not all exploits will use something like JS to obfuscate their existence and frustrate analysis.
Also remember the famous sayings "Those who give up freedom for security deserve neither" and "Live free or die". Accepting the insecurity, because freedom cannot exist without it, is also important.
"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety"
The extra words are important
Also the background context of arguing for taxing the rich instead of making them aristocrats.