While my experience is on Windows, and with Chrome, I have also had a similar issue.
I ended up tracking it down to the fact that on start-up, over time a lot of junk got added into the applications/services that run on start-up. To the point that it would slow down Chrome when I tried to open it right away.
So a potential solution to your problem is to check out what else is running at start-up that might cause FF to run slow, but only at start-up.
You have a very unique perspective on advertising. I do not understand how you distinguish honest communication attempting to convince you to buy something versus some forms of advertising.
Additionally, you make this appeal to what is natural, implying that natural is better. You seem to be defining natural as something that you would do without money informing your decision, but no one is a machine that makes all or even many of their decision on conscious thought.
Additionally, you don't seem to understand either that Troy runs a service Have I Been Pwned, for free, and there is no advertising there at all. The ads that he has aren't just funding his $20/month blog, but a service that tens of thousands of people rely on, and can easily cost him $1000s of dollars per month (he has made some posts on this previously).
Laaastly. Regarding your last claim of "adblock blocks his source of revenue"... Are you running adblock right now? Does it even block his banner? I doubt it.
I ended up tracking it down to the fact that on start-up, over time a lot of junk got added into the applications/services that run on start-up. To the point that it would slow down Chrome when I tried to open it right away.
So a potential solution to your problem is to check out what else is running at start-up that might cause FF to run slow, but only at start-up.