The studies are right and the takeaway is wrong. Take a set of three reps at RPE 9 and a set of thirty reps at RPE 9, match them for effort, and the muscle grows about the same. Schoenfeld's load work has been replicated enough times that I no longer argue it. Light weight to failure builds muscle. That part is settled.
Then someone reads the abstract and decides load does not matter. That is the trap.
Load does not matter for hypertrophy in a lab, where muscle thickness is the single output measured and the researcher's time is the single cost. It matters everywhere else. A set of thirty leaves you face down. A set of three leaves you ready for the next one. Match two protocols for growth and they are still not matched for fatigue, for joint cost, or for the time it takes to reach failure on a movement that matters.
I train heavy because the goal is never only size. I want the size and the strength under the same bar. Thirty reps of leg press gives me one of those. A heavy triple on the squat gives me both, and it gives me a number I can chase next week. Strength is the thing that compounds. You cannot autoregulate a burn. You can autoregulate a top set.
The reps-to-failure crowd will say the heavy work costs more recovery. Sometimes. But a high-rep set carried to true failure is not free either, and most lifters who quote the studies are not actually training the light sets hard enough to make the comparison hold. They read "light weight works" and they train light and easy, which is neither protocol. The equivalence only exists at matched effort, and matched effort with light weight is brutal. Almost nobody does it.
So I program low reps and meaningful load for myself and for clients past their first few months. Not because high reps fail to build muscle. Because the heavy work pays twice, and the lab only measures one of the payments.
If your goal is purely a pump and your joints are unhappy under load, train light and train hard. That works. I just want the strength too, and I am not willing to trade it for a protocol that grows the same muscle and leaves me weaker.