1. Software has bugs.
2. Bugs which interface with and execute untrusted code are high risk.
3. Browsers are obscenely large pieces of software, which connect a user’s system with random websites which execute JavaScript.

Browsers are one of the most important things to update on your computer.

We can talk about whether browsers should be as complicated as they are, but implying security updates are a intended as a vector of control is conspiricist thinking.

The reason you don’t get security updates backported to your older release of choice is simple: it is so much work.

Waterfox seems like a good choice, just don’t go around thinking that companies are making security updates in order to sneak in unwanted, they make security updates because they are terrified of being responsible for a major incident.

If any were it’s not like we would know, secrecy being rather important to that kind of activity.