Would Wilder be even more difficult to fight if fights were 15 rounds like the old days? He can carry his power all 15 rounds, he might get out-boxed for 14 rounds but find the KO in the 15th. Heavyweights would have to survive 3 more rounds, look at Fury he survived 11 rounds, and then got his lights put out in the 12th. If Fury had to box 3 more rounds most likely he would've got stopped
Indeed he did, but it sure as hell wasn't easy despite what you may think. Fury suffered two knockdowns in the process and openly admitted he was never hitten that hard in the ring ever. Wilder can be outboxed, but I can imagine it to being a highly stressful experience considering one mistake could immediately end your parade. Also, Wilder's style isn't about winning rounds. It's about catching his opponents and pasting them on spot. His entire strategy is based on that.
Well let's get more extreme and hypothetically increase the rounds ad infinitum. I think Wilder benefits as Scar has said his style is to wait and see, survive the rounds and find an opening to KO his victims. Wilder is so skinny and has so little muscle mass (using up oxygen) that he could probably perform for 20 or 25 rounds at his slow pace and work rate. So yes, the more rounds it more suits his style.
That is not even "a style". It's just using an advantage. He actually tried to box against Fury, but he was outboxed. I don't doubt his power... The difference is he never tried to box againt Ortiz. He doesn't like to get hit at all especially against heavier hitters.
His entire style revolves around his advantage. That advantage is simply good enough to take him this far. Murderous punching power, basically. If that can be resisted, he's done losing. That has been proven already in the Tyson Fury robbery.