PopOS is in a rough state. The stable ISO is using absurdly an absurdly outdated desktop, and the beta using COSMIC desktop. I personally love COSMIC, but it is far from stable, so I would not recommend it to most users.
CachyOS is a great distro. The performance gains from its changes won't be huge, but the people acting like its nonexistent are silly. They also make many upcoming performance improving features like NTSYNC available early in their default kernel.
I definitely wouldn't go Debian or Mint for gaming personally. I don't like stable distros with such slow release schedules for gaming, mainly because of stuff like the prior mentioned NTSYNC. You don't get those new features for a long time.
I saw people recommending Bazzite, which is a distros I highly recommend. The only issue I have with Bazzite is that installing kernel modules they don't ship is pretty much unsupported and requires a lot of jumping through hoops. Most people won't need this, but it matters from some use cases like if you need steering wheel drivers.