It's actually harder to do synchronous floppy I/O on the Amiga. Data transfer is done over DMA, then you perform MFM decoding. The latter can be done by the CPU, or, asynchronously again, by the blitter, in which case you can't use it at the same time for graphic operations.
Depending on what you are going for in terms of gameplay experience, that can be a reasonable trade off. Say an RPG where you page in/out assets as needed but doesn't break the flow is probably going to be a bigger issue on gameplay styles that need more compute to achieve.
