Can someone please explain something to me? I’ve had this question for a long time, and finally decided to ask it... Why does anyone rely on TOR for security?

Can someone please explain something to me? I’ve had this question for a long time, and finally decided to ask it... Why does anyone rely on TOR for security? Obviously bugs happen, but it seems pretty easy to hack by any large organization....or government. For instance, according to this page ( https://metrics.torproject.org/networksize.html https://metrics.torproject.org/networksize.html ), there are less than 7,000 relays in the TOR network. To me, the US, British, Russian, or Chinese government could easily control most of those (i.e. running their own nodes) without anyone knowing, and use that to listen in (or at least infer) what TOR users are doing. At that small of a scale, I’d bet a large corporation could even run a bunch of nodes. How can that be protected against - or can it? Am I missing something?