Adam Gontier from Three Days Grace is one of the best vocalists of all time. I've heard many singers from so many different genres but there are very few who can do what he has done. I've never heard anyone mention his name when they discuss the all time greats. Just go and watch a random live performance from him. Even in an acoustic setting his delivery is perfect. People might get triggered to see a "butt rock" singer in the same conversation as Plant, Mercury, Cornell etc. but it is the reality. Range, feel, power, clarity, stamina, intensity he checks all the boxes.