Depth isn't necessarily all that anyway.
I used to be a very deep squatter and all it was is that I'd become accustomed to sitting back on my legs. You can generate a bounce on that. If you asked me to squat to parallel at the time, I'd hate it because I wasn't trained for arresto momentum at that position - so actually, parallel was much harder for me.
Yes going below parallel is an arbitrary thing and for muscle building not necessarily that important. Depends on what you're trying to hit and if you think working at maximal muscle lengths is critical like Israetel says LOL. But clearly you can build a lot of quad mass with shallow squats too. I tried increasing the stretch on leg extensions and had a tear that prevented leg training for a couple of months

I love sitting in the bottom position on squats for a couple of seconds though.
I mentioned Joel Steedman upthread. That guy is a joker too IMO, only in the other direction
