How fast can you actually print? Flow = layer height × line width × speed. Compare it to your hotend's melt limit and get the real max speed.
Volumetric flow = layer height × line width × speed. 0.2 × 0.4 × 60 mm/s = 4.8 mm³/s, easy for any hotend. Ask for more than the hotend can melt and you get under-extrusion regardless of what the slicer says. The limits above are ballpark; PLA flows more than ABS/PETG at the same hotend.
The volume of plastic the hotend must melt per second: layer height × line width × print speed. At 0.2 mm layers, 0.4 mm lines and 60 mm/s that is 4.8 mm³/s. It is the real speed limit of a printer.
The extruder pushes faster than the hotend can melt, so lines come out thin and weak (under-extrusion), often with clicking or skipping. If a fast profile prints badly, this is the first thing to check.
Ballpark: classic V6 or MK8-style around 11-15 mm³/s, Revo and Dragon around 24, high-flow units 30-40+. It also depends on material and temperature; the printed maximum is usually quoted for PLA.