Yes but if someone's following a traditional strength routine, why would they ever want to do 3x20 on hack squats? Even a hypertrophy routine wouldn't see you hitting those sorts of reps. So yes, it certainly won't take you long to out grow 100kg with deadlifts or squatsEspecially if like Tom you've been quite a big lad prior to lifting.
oh dear. You're one of the people that claims it has to be 8 reps or less to be considered a 'strength routine', aren't you? dear me.
Have a google at some reasons one might want to incorporate a 20 rep squat set into their routine. You might learn something. Typically, a person wouldn't do 3 sets, maybe 1 or 2 - but apparently 100kg is a peanut to him, so whats 3 sets of peanuts.