If power was everything, Ernie Shavers would have been heavyweight champ a long, long time! However, power is the one thing that instantly can change the outcome of a fight. However, as master boxers will prove, "you can't hit what you can't find" so all that power leads to draining your stamina when you miss. A fighter with great timing, not necessarily "speed", will win everytime.
Hypocrisy set aside and exception taken to highly skilled opposition, power combined with a good chin and athletic ability is more than half way to victory. People gat to see - why is that technically superb artists come short to impress against their technically inferior opponents? Simple answer would be that these opponents don't respect their punching power... Without going too much into detail, it stands to reason that every single punch is likely to cause brain tissue damage and haemorrhage inside the skull - therefore, defense should be important but not as important as commiting yourself to the punch and when you achieve to do so, you can inflict damage. Boxing is a blood sport and is cruel so if you don't have the tools, what r you gonna do? Negative boxing, waltz sessions, fighting masquerades? It would be much more simple to exercise your defensive skills in martial arts exhibitions and that is the naked truth... Boxing still is kill or be killed in my view.