Training to volitional failure produces similar hypertrophy across different loads, but high loads produce greater strength and rate of force development improvements than low loads.

Study: Low-Load Resistance Training to Volitional Failure Induces Muscle Hypertrophy Similar to Volume-Matched, Velocity Fatigue

When you lift light or heavy weights until you can't do another rep, you grow similar amounts of muscle. But lifting heavier weights makes you stronger and faster at moving things than lifting light weights, even if you go all the way to failure.

Study: Impact of high versus low fixed loads and non-linear training loads on muscle hypertrophy, strength and force development

When people lift weights until they can't do another rep, they grow similar-sized muscles whether they use heavy or light weights. But only the heavy weights make them stronger and able to push or pull faster.

Study: Resistance Training Load Effects on Muscle Hypertrophy and Strength Gain: Systematic Review and Network Meta-analysis

The study shows that lifting weights until you can't do more leads to similar muscle growth no matter the weight, but heavier weights build more strength, which matches the claim.

Study: Impact of high versus low fixed loads and non-linear training loads on muscle hypertrophy, strength and force development

This study shows that lifting heavy or light weights to failure makes muscles grow the same, but only heavy weights make you stronger and faster at producing force.