It's really irritating that 99.9% of men's underwear has insufficient specificity in sizing. Seriously, only 5 sizes for everybody? What the heck are they thinking? With how many millions of pairs are sold every month, you'd think they could have more, like 15 or 20 sizes.

Also, I hate the elastic waistbands that are used as a crutch for wildly inaccurate sizing. On every pair of underwear I have, either the waistband is too tight or the rest of it is too baggy. And i'm not fat at all. My body mass index is completely average (Rather below average, considering I live in the USA).

If it's sized properly it should apply no more pressure than the minimum that is necessary to prevent it from falling off. Every underwear I've tried applies several orders of magnitude more than that, or else falls off. I've tried taking underwear that fits perfectly, except for the elastic waistband that applies too much pressure, and stretched it out as much as possible in order to weaken the elastic. That helps a little bit.