If you take your gaming setup seriously, you've probably invested in a quality chair, a decent monitor, the right peripherals. But gamer underwear tends not to make the kit list even though it's the 1 piece of gear in direct contact with your body for the entire session. I think that's an oversight worth correcting. The best gamer underwear is comfortable enough that you stop noticing it within the first 10 minutes and stay that way whether you're 30 minutes into a casual session or 6 hours into a tournament.
What I think the best gamer underwear achieves is removing 1 more physical variable from a setup that's otherwise been optimised for comfort and performance. Serious players think about eye strain, posture, hydration, and input lag. Underwear comfort is in that same category of physical factors that affect performance over a long session. Getting it right means 1 less thing drawing attention away from what you're actually doing.
I know a bloke who streams long sessions regularly and started taking gamer underwear seriously after a viewer jokingly asked if he'd been uncomfortable during a particularly long stream. He tried Barramundies and reported back that comfort during long sessions had genuinely improved. He said he'd adjusted his position less during the session, which his body had apparently registered as physical relief even if he hadn't consciously noticed it. That's the kind of incremental improvement that adds up over a long streaming career.
In my opinion, the best gamer underwear is just quality underwear chosen with the specific context of extended seated use in mind. Barramundies delivers comfort that holds up across whatever duration your session runs to. If you've optimised your setup in every other way and haven't thought about what you're wearing while you play, this is the easiest remaining upgrade on the list.