[mo]

Anecdotally, I used to be in control of more than half of Tors exit capacity (until I had inspired enough other people to take over), with no association to US TLAs, and I personally know many exit and other relay operators. I have no reason to assume they are affiliated with US TLAs or other TLAs. The majority in terms of numbers may be, but not the majority in terms of bandwidth.

Personally, I doubt the US TLAs have a need to operate any relays themselves. They can simply wiretap, and use control flow data for correlation when necessary. Tor can still be useful for all those who do not try to hide from the few agencies who may have this kind of visibility.

The relay community is pretty good in terms of interacting with each other. There are real-world meetings to get to know others in the space, which may make you also more comfortable seeing their personal reasons for providing bandwidth.