Failure has it's place in your training program(s). But like anything, do not use it too often or too frequently.
Regarding hypertrophy and what will stimulate your muscles to grow and whether or not you use drop sets, failure or any other host of techniques depends on your amount of training volume, how often you train, sleep/recovery, amount of food and of course the old adage "genetics."
Sometimes people use genetics as a cop out. If they don't know what they're doing or something is not working for them, they just say "I guess my genetics suck, I've tried everything! And I mean everything." You then ask them 'What's everything entail?' and they can't tell you or it's far from actually being everything. To them "everything" means either high reps or low reps. Nothing in between.
Muscles respond to Time Under Tension & this is a good way to be able to things consistent enough and be able to later alter your program. Using a specific rep range with a prescribed tempo will give you an approximate idea as to how much time your muscle is under tension. 10rps at a 301 tempo will make the set 40secs long (10 reps multiplied by 4secs per rep). So because you don't go to failure, you won't grow? That is what some here are dictating. The other people are saying you have to make sure you're failing around that 40 second mark in order to grow. What if I did 9 reps equaling 36secs total, but threw in a last failure rep that caused me to only do 37secs total...I must not grow because I went to failure (according to TBombz). Or will I? According to Basile I need failure.
What works? Neither and both!
Instead of saying you tried "everything" and you are still failing to progress in the way you would like, take a look at your program more in depth. Sure, you're lifting 20lbs more on a lift yet still not growing. Maybe you're not growing because even if you're getting 8-10rps (the usual protocol suggested to grow/induce hypertrophy) yet completing that set within 15-20secs, that's why you're not growing. Muscles usually need more than 20-25secs under tension to induce hypertrophy.