Personally I use meundies long boxer briefs. They run a little small. I'm a big guy, 40-44 waist, usually for shirts I wear a 2x, 1x if it runs big. I need to go 3x in meindies and even then they're a little tight, but not uncomfortably so.
They last a while, I've had a few pairs for a few years now. I'd recommend joining the membership (no fees, cancel anytime, postpone anytime) and get a pair. If you like them, get a new pair every month or two. Till you fill out your closet.
They're a little pricey at close to $15 - $20 a pair, but they're fun patterns and decent quality if you feel like splurging. But get ready for ads on every ither youtube video for the next year if you even go to their website
I'm definitely not below average in that department, and I'm fine with it. It is a mostly spandex material, so it'll stretch for days. The pouch doesn't have any empty space for sure, but I'm never feeling compressed down there. And if you get the long boxer briefs, then you can pull the legs up a bit to get extra room for the jewels if you need it