How do people make their last sets the heaviest??

I dont understand how people make their last set the heaviest of all the sets.. say for example you do 3x5 on squats, how are you making the last set the heaviest?

surely you are wimping out on the first 2 sets? for example my 5 rep max on squat is 100kg. I can do 100kg if I make it my first or second set, but if I try to make it my 3rd set after doing 90kg first, I will fail as I am tired by this point. I could probably only make my 3rd set my highest 100kg set by dropping the other sets to about 70-80kg.. but that would be easy as hell and feel like a waist of two sets.

I usually leave around 3-4 minutes rest between sets. Are you "last set max" brahs making your first couple of sets about 70-80% of your rep maximum to achieve 100% on your last set?
Not only do I not understand HOW some people are able to make their last set the heaviest, I also dont understand WHY they make it so.

Explanations needed please :)

Text for 20 minutes

20k x5, 20k x5, 20k x5, 120k x1.

Thats what I usually see...

Personally I start with my most demanding lift, go as heavy as I can on set 3, 4 and 5 taper off, then the rest of the workout is at weights that I know I can move comfortably with good form.

20k x5, 20k x5, 20k x5, 120k x1.

Thats what I usually see...

Personally I start with my most demanding lift, go as heavy as I can on set 3, 4 and 5 taper off, then the rest of the workout is at weights that I know I can move comfortably with good form.

just work your way up to it in weight

I used to do this. Currently, I do like three sets, sometimes four for an exercise, sometimes only two. first set a bit lighter, second set heaviest and third set maybe go down in weight and focus more on the feel of the exercise.

just work your way up to it in weight

I used to do this. Currently, I do like three sets, sometimes four for an exercise, sometimes only two. first set a bit lighter, second set heaviest and third set maybe go down in weight and focus more on the feel of the exercise.

My last set is always my heaviest as well.

I do 3x5 and up the weight 10 lbs every set. If I fail at a specific weight two sessions in a row, I'll reset.

i guess it's like warming-up at the heavy end of the scale. Sometimes il go 'fairly' heavy on first set, then il just add slightly more weight each set until my muscles cant take anymore - bit like what you said in your post - start at 70%, then 80%, 90% end on 100%