Wilder landed every big punch in his arsenal vs the French heavyweight, Dahaupas, and couldn't get him outta there. He had him hurt early in several rounds but simply couldn't finish the job, despite landing several full power right crosses and uppercut combinations.. I'm sure he's more powerful since then, but one has to wonder, can Ortiz take a punch better than Dahaupas? If they're near the same level of punch resistance, that's Wilder's ass.
Look at the size of Ortiz's head/neck and overall thickness of his body and that will answer you question. Wilder's long thin neck ain't going to stabilize his head. Wilder's chin is also naturally shaped outwards.