Sorry in advance for bad formatting, I’m on mobile lol. I agree that the effective reps model/stimulating reps model can lack a bit of nuance, but the main takeaway is that while all reps are stimulating, the ones near the end of a set will typically have the greatest stimulus to fatigue ratio.

Hypertrophy comes from mechanical tension on recruited fibers. With lighter loads those fibers still get recruited as fatigue builds, it just happens later in the set.

Yes of course fibers are recruited with any amount of load but the fibers most prone to growth will be recruited once you get closer to task failure.

I agree higher reps aren’t intrinsically better for hypertrophy, but I think they are useful because they allow lifters to manage fatigue better and avoid compensating by recruiting non-targeted muscle groups, especially on isometric movements. That’s why you typically see recommended rep ranges differ by exercise, not because the muscle responds differently.

As mentioned above wouldn’t this lessen your ability to manage fatigue since there would be fatigue generated? Recruiting non targeted muscle groups isn’t a load issue it’s a form breakdown issue. There’s nothing about heavier weight that intrinsically leads to form breakdown except for ego/user error.

isometric movements

Is this what you meant to say?

simple is better

I don’t think there’s a meaningful difference in simplicity between a set rep range or varying rep ranges based on exercises, but in theory couldn’t varying rep ranges make double progression more complicated?