I just don't think Tor Browser is currently suited as a primary browser for most people. You lose things like staying logged into websites, you can't (or at least shouldn't) really add extensions like a good content blocker, you generally can't tweak or customize the browser to your liking, etc. Plus factor in things like the slow speeds, being blocked by websites, bombarded with captchas everywhere, etc, and it just becomes a harder and harder sell for a lot of average people.
Tor Browser's great and it absolutely has its need and purpose, I'm not trying to knock it for that at all because it works damn well for what it is and what it tries to do, but I just think its hard to be using as a primary browser and daily driver in its current form, at least for a lot of people.
So when I first learned about TOR almost 10 years ago in uni, it was said to be compromised to a significant extent by secret services holding entry and exit nodes.
I also heared that bit about the secret service owning nodes a few years ago. It was trough a teacher that's also really in the stuff outside of teaching, and has a network of non-teaching proffesionals in the field.
It's something to keep in mind, at the very least. Tor already has some weaknesses anyways. You shouldn't trust it blindly just because it's Tor. If anything, I think it more has a false rep for how strong it is over struggling with a stigma.
Iirc holding both the entry and exit of a routed connection, you can in theory match traffic going through, which would let you connect a user to the server/site they are connecting to. It might still be encrypted at that point, idk the details anymore.
I don't think a single credible source has shown this to be a vulnerability. You're talking about an attack that would cost, what, millions of dollars to run per day?
No. Use it for everyday tasks. If Tor is used by only people who need them, they will be easily detected. The whole reason US Navy released Tor to public was so normal users can scramble the usage detection. One more advantage is that right now lot of website block tor users if more users will use tor then they might stop it.