not an expert, 2 years of serious lifting, but this is probably a good adage for the average person from my current understanding
training to failure puts you at higher risk of injury and there are diminishing returns as you approach your 1 rep max and/or failure
hypertrophy can happen with more reps or more weight
strength gains are usually just focused on progressive overload
though, of course, hypertrophy will happen either way and contributes to increased strength, but this seems to be further confirmation that you can gain muscle size either way