Not so sure that's true. This is single-threaded direct I/O doing a fio randwrite workload on a WD 850X Gen4 SSD:
write: IOPS=18.8k, BW=73.5MiB/s (77.1MB/s)(4412MiB/60001msec); 0 zone resets
slat (usec): min=2, max=335, avg= 3.42, stdev= 1.65
clat (nsec): min=932, max=24868k, avg=49188.32, stdev=65291.21
lat (usec): min=29, max=24880, avg=52.67, stdev=65.73
clat percentiles (usec):
| 1.00th=[ 33], 5.00th=[ 34], 10.00th=[ 34], 20.00th=[ 35],
| 30.00th=[ 37], 40.00th=[ 38], 50.00th=[ 40], 60.00th=[ 43],
| 70.00th=[ 53], 80.00th=[ 60], 90.00th=[ 70], 95.00th=[ 84],
| 99.00th=[ 137], 99.50th=[ 174], 99.90th=[ 404], 99.95th=[ 652],
| 99.99th=[ 2311]
