There’s always a workaround for a pedal wrench, and if you rare install or remove pedals and are on a strict budget, skip a pedal wrench. Otherwise, don’t skip. The long lever and a slightly offset head makes it easy to remove pedals installed with too much force, and keeps your knuckles away from the chainrings, so if you goof, you still won’t get cut up.
All normal adult pedals take a 15mm wrench. A small handful take 8mm hex wrenches (allens); and some fit both. If you work on your own and your friends’ bikes, this is a good tool to have.