I don't think so? If last week I could do 50 reps @ 5 lbs, and this week I can do 50 at 6 lbs (or 60 at 5lbs), then that's measurable objective progress

isnt the 1RM the measure of progress?

If that's what you're training for, sure. If you just want to be strong, you can achieve that and avoid the highest injury risk by sticking with 5 reps or so.