A perfect LSAT score is 180 — and almost nobody needs one

So 180 is perfect in the sense of being the top of the scale. It is not necessarily perfect in the sense of missing nothing — the raw-to-scaled conversion varies between forms, and on some forms a small number of misses still converts to the top score.

Why the last points cost the most

Improvement on the LSAT is not linear in effort. Early gains come from learning what the question types ask for, which is a large amount of score for a moderate amount of work. The final stretch is different: you are hunting individual questions, each of which was written specifically to defeat someone who is already good.

The practical consequence is that the months spent moving from very strong to perfect are months not spent on the application, and they buy less than they appear to. A committee comparing a 178 and a 180 is, for almost every purpose, comparing two people who are the same.

The measurement argument against chasing it

That is LSAC saying, in its own materials, that a two-point difference near the top is inside the instrument's error. Chasing a specific number at that end of the scale is chasing precision the test does not claim to have.

What to aim at instead

Work from the schools on your list. They publish the medians of their entering classes, and being comfortably above those medians is what changes admission decisions and scholarship offers. Above that point, additional score does progressively less.

There is one honest exception. If you are targeting the very top of the scale for its own sake, and you have time you are not taking from the rest of the application, that is a legitimate choice — just make it deliberately rather than by drifting into it.

What a perfect score does not do

It does not admit you anywhere by itself. The GPA is still there, the file is still read, and schools reject high scorers every cycle. A 180 is a very strong number attached to an application that still has to be good.