I don't often need to unless I'm wearing briefs, which is rare.
Briefs became annoying to me about 6 years ago. Once I went to boxers or freeball, I haven't been able to wear briefs anymore. Briefs look hot, but it's very rare that I'll wear just my underwear, so how they look is irrelevant. For me, they're uncomfortable to wear.
Well fitting underwear minimizes a lot of this.
It depends on what type. I've bought pricey briefs and boxerbriefs that I won't wear anymore. If you buy briefs snug enough to hold everything in place, the tightness is uncomfortable. If you buy them a little bit larger to give some extra room, the leg openings sag, your balls will fall out the side and get pinched, and inevitably, your dick drops down where your balls are and gets squished.
For me, there was too much drama having to adjust constantly. I quit fighting it. Boxers or freeball became the only way to go. Everytime that I go for a bike ride and wear my cycling gear, I'm reminded of how much I dislike tight stuff around my crotch. I have to deal with it when I'm riding, but all other times, I'm loose and free.