The funny part was that I had similar issues just before that. When I got there the squat rack was being used, I asked and the guys said they had 3-4 sets left. I said cool and started with something else and came back. After I got on a guy asked if he could jump in with me and it wasn't an issue. When you ask how many sets they have left and they say two AND its a different exercise than you. Just go do something else. And it wasn't like I was on my phone in between sets.
Yeah, I usually do legs on Thursday, Friday or Saturday for that reason. The gym is thinned out on those days.
Mondays and Tuesdays are packed. I don't even bother planning legs on those days. My gym is a newer Gold's Gym with limited free-weight equipment. It sucks. But it's cheap and has a lot of pawgs, so... mas o menos, it's all good.