> Because game studios these days are all about global matchmaking

Why not have moderation then? When participating in an online forum, you are essentially "matchmaking" to a topic or corner of the internet with similar interests. Have some moderators (be it members of the community, or staff) ban players on obvious hacking/cheating or rule-breaking behaviour, and allow members to report any instances of this (I believe this is already a thing in modern video games, I have seen videos of "influencers" getting enraged when losing and reporting players for "stream sniping").

Sure, this might cause the usual issues of creating an echo chamber where mods and admins might unfairly ban members of the community. But you could always just join a different server in that case.

I believe Minecraft has a system similar to what I described; you enter the URL of a server to join, each hosted on its own independent instance (not necessarily hosted by Mojang, the studio behind Minecraft) each with their own unique sets of rules and culture, and being banned in one server does not ban you from every other server. Incidentally, Minecraft also does not have kernel level anticheat, and still very successfully manages to be one of the most popular games around (By some accounts, the top-selling game of all time).

> I miss the days of Tribes 2 or CS1.6 when games had server browsers

I do too.