I'll go against the grain and say player, but I'll provide specific circumstance. Being a player at a table with a much less experienced GM can be difficult. I've found myself in this position and several rulings being outright wrong, some of the other players taking advantage of the GM's ignorance on certain details. In those moments, I try to help others understand how some things work if they ask (very important). The GM may not necessarily be struggling, but it can be a challenge to enjoy the game as a player at table where everyone else is much less experienced, especially the GM. (Note, a fair amount of this perspective comes from two different GMs "in training", each about 1/3 my age.)

Generally speaking, a lot more effort and focus is required to GM. Unless, of course, you improvise everything (and your players are ok with that/don't notice).