I've installed gentoo but there seems like there's so many sacrifices. I love that it's all open source, but I really don't mind closed source software now and then, because after all I would be using it to play closed source games. The biggest compromise I've observed is the very long build times. I have a lukewarm cpu(i3 10100) and it's powerful enough for good gaming but the build times are still like 10x minimum for some software. All this to say, is using gentoo really worth it? I love the idea behind it, and if I was doing criminal activity I'd definitely use it, but is there some absolute upside to it or is it a really good OS for privacy that sacrifices in usability?
Privacy and usability are inversely correlated. Anyone who tells you otherwise either has a relatively weak definition of "privacy" or a relatively exotic definition of "usable". If you're at the point of installing an OS like Gentoo just for its privacy benefits alone, I'd say you're already the latter case, even from the perspective of most fellow Linux users.
Of course, that doesn't necessarily imply very un-private software is always very usable, or that highly privacy-respecting tools with good UX don't exist. Just that most highly UX-polished software tends to have poor privacy, and most privacy-focused software expects the user to do a lot of hoop-jumping to make up for all the systems and workflows the user can't utilize due to having some dealbreaking non-privacy-respecting component to them.