Hrm "unlimited IOPS"? I suppose contrasted against the abysmal IOPS available to Cloud block devs. A good modern NVMe enterprise drive is specced for (order of magnitude) 10^6 to 10^7 IOPS. If you can saturate that from database code, then you've got some interesting problems, but it's definitely not unlimited.
Technically any drive has a finite IOPS capacity. We have found that no matter how hard we tried, we could not get MySQL to exhaust the max IOPS of the underlying hardware. You hit CPU limits long before hitting IOPS limits. Thus "infinite IOPS."