There are a few issues with taking every set to failure, the most important being that it will substantially increase your risk of injury. It sounds great until you consider compounds like the deadlift that can ruin your back if your form is bad, and by definition, going to failure means your form will be imperfect at some point. There are lots of macho powerlifters out there with permanently ruined spines who will probably die earlier than they would have otherwise, due to mobility degradation.
Particularly as you get older you become more injury prone and your recovery time slows down. This necessitates being cautious about how quickly you increase weight and how often you go to failure.
The better goal to target is increasing volume, where volume is defined as Sets x Reps x Weight. The literature doesn't conclusively establish that any one of these is "more important" than the others for hypertrophy. The only real caveat when you follow this rule is that at a certain extreme of low weight / high reps (like 50 reps) you wouldn't actually be doing resistance training anymore, it'd be cardio.
Particularly as you get older you become more injury prone and your recovery time slows down. This necessitates being cautious about how quickly you increase weight and how often you go to failure.
The better goal to target is increasing volume, where volume is defined as Sets x Reps x Weight. The literature doesn't conclusively establish that any one of these is "more important" than the others for hypertrophy. The only real caveat when you follow this rule is that at a certain extreme of low weight / high reps (like 50 reps) you wouldn't actually be doing resistance training anymore, it'd be cardio.