general rule of thumb that most strength people will say is squat 140, bench 100, dead 180 (in the US they say squat 300lbs, bench 200lbs, dead 400lbs)
That is a Novice level.
that is for single reps obviously.
From what I've seen, it is quite common for people to be able to squat 160, bench 100 and dead 180.
for the average male who is newish to lifting and is an average 5'9" and say 75-85kg.
It really is a "piece of string" question though.
I'd say that when you get to a 4 plate squat, 3 plate bench, 5 plate dead (180, 140, 220) at a body weight of 80-85kg you wouldn't come last in a comp, but you'd be closer to the bottom of the list than that top.. ask me how I know.. lol
Heel for the squat is helpful if you don't have as much flexibility in your ankle area.
if you squat with a narrow stance, you tend to have your knees going forward more which means more bending at the ankle.
a wider stance will have you sitting back more so your ankles don't bend as much.
example..
olmypic lifter style squat
Powerlifter squat.