Seriously. How can you load up your barbell properly for a warm up or a set if you don’t remember your 1RM?
How can you know if you improved on your previous Fran time?
How will you know the proper scale for you?
How will you become better?
Figure out a way that works for you, but know your numbers.
Know if 65# OHS is too heavy or too light. Know what 85% of your 1RM is. Know if your mile repeats are leading to improvement.
It is one of the easiest, pain free ways to help you succeed. All it takes is a little brain power, and a little time.