I use Orangefren these days, and I assume that the reason why these two exchanges are the "most popular" is that the aggregator recognizes them as the most favorable.
Unfortunately, FF has a very bad reputation, but such warnings do not exist on Orangefren. Also, I contacted Exolix directly and did not get any guarantees from them that they will not freeze funds and require KYC.
I'm glad you're using the site!
I'm not sure what you mean, we've had a warning for FF for years now. (Notice the dark
yellow text).

Exolix guarantees never-KYC only to users that use our link. It doesn't mean they'll definitely process whatever coins are sent to them, but they will offer a no-KYC refund if they don't like them.