but there are many known attacks which can be used against Tor, plus possible 0-days against the browser, so you can never feel 100% anonymous.

Also, even if you treat Tor as perfect, it's really difficult to remain consistently anonymous; for example, you might via Tor use the same email address to order something shipped to you as you use to speak out against your oppressive government, and that's a link that can be exploited. Even though Tor is pretty flawed, being far behind state-of-the-art research, it's these non-Tor anonymity failures which almost always get people. This was the case for Ross Ulbricht, for example. As I always say: if you think that you're perfectly anonymous, then you're wrong. Think of even the best anonymity tech as a light bulletproof vest which will increase your survivability a bit, not as an impenetrable wall.