Bought a few $10 pairs of gym shorts from a big box store, probably an 8" inseam. I wear boxer brief style compression undies when I run, so netting and how they feel on my skin isn’t really an issue. They have side pockets that are fine for carrying my key fob, which is the only thing I really need for most runs. On runs they seem completely adequate. What am I missing by not wearing more expensive or nicer shorts purpose made for running? Is it one of those things where if I try something nicer I won’t be able to go back?
By shorts of you mean underwear, not much except to look out for the material. Cotton ones in long runs will become so wet and make you feel a little uncomfortable, but not a deal breaker. Personally I find the smooth ones with chemicals stuff nicer. (Sorry for not knowing the name.)
The outer layer can have double layers thus putting insulation to keep your thighs warm. This is especially important in winters. If you can find a cheap pair that does this, good. The mid-tier from Decathlon is good enough.