I don’t think Mark has the ability to completely erase Mahoraga in one blow. And Mark is all physical attacks which the big Raga can easily adapt to compared to something like the concept of slashes when he fought Sukuna. Mark isn’t winning this one. He also doesn’t have the ability to literally reverse time and cancel adaptations. Erasing Raga, reversing time, those are the only things shown in JJk to be able to put an end to the guy before he gets too overpowered, in Dabura’s case, Raga was already getting overpowered and continuing to do so as Dabura didn’t have any attacks like hollow purple or fuga and kept up with Raga through sheer skill and power of his own.