[hombre_fatal]

They could be talking about dumbbell weight, as 10lb is entry level but 50lbx10 requires some shoulder development.

Either way, I don't see the issue with doing 50 reps of something if you're failing at the end. The main issue is that it's boring and more mentally taxing than 6-10 reps I think.

There's a Huberman Lab podcast with some expert who also says the ideal rep range is anywhere from 6 reps to 30+ reps to make the point that we overly fixate on it. Lifting something until you can't is the operative goal.

I personally like drop sets for this purpose (decreasing weight until failure) because you end on a lighter weight that won't hurt you if something goes wrong, but you aren't stuck lifting one weight for too long.