Speed on a core-xy, especially acceleration, can be a ton higher than a bed slinger. I have a 350mm^3 Voron keep a 0.6mm nozzle on it, and print with 0.9mm line width and 0.3mm layer heights. I have a Rapido HF and volumetric flow winds up being my bottleneck most of the time.

Also note that when you’re going fast, material matters a lot. I can melt ASA faster than PLA/PETG. But… ASA can be a bit more melty so things like overhangs can suffer. And the whole needing a heated chamber thing.