Quality reps or intensity

When doing backoff sets, is it better to prioritise quality reps or high intensity reps?

Here's my back story: Ive been trying to figure out what i should prioritise regarding my backoff sets when squatting. Im getting into powerlifting, and ive made a program for myself, but im uncertain about some of my choices. (Wont post it here now due to subreddit rules) For starters, start off one of my leg days with 4-5 ramp-up sets till i reach my top set of 3 reps. Today, i did 105 kg for my top set, and then i did 3 sets of 90 kg backoff sets. (Ended up doing 7, 6 and 6 reps. My rep range is set to 6-8 reps). I stopped when i felt my form is starting to deteriorate, but the sets were still quite tough. When i asked some of my friends, they suggested doing 4 sets of 5 reps instead, but i thought intensity is what stimulates hypertrophy. Am i doing something wrong?

I finished my workout with: 3 sets of pendulum squat (8 reps 30 kg, 8 reps 32,5 kg, and 6 reps 35 kg) 3 sets seated leg extensions (8 reps 75 kg all 3 sets) Seated hamstring curls (8 reps 75 kg all 3 sets) Hip abduction (8 reps 103 kg all 3 sets) calf raises (10 reps 135 kg all 4 sets)

I appreciate the help in advance