That is a bit of a unfair comparison. The Hetzner and DO instances are shared hosting, you are using dedicated ressources.
Using a Netcup VPS 1000 G12 is more comparable.
read: IOPS=18.7k, BW=73.1MiB/s
write: IOPS=8053, BW=31.5MiB/s
Latency Read avg: 5.39 ms, P99.9: 85.4 ms, max 482.6 ms
Write avg: 3.36 ms, P99.9: 86.5 ms, max 488.7 ms
Hetzner has dedicated resources too, but they also have 2 levels of shared resources, "Cost-Optimized" and "Regular Performance". The 3900 IOPS CX23 above is "Cost-Optimized".
Here are some "Regular Performance" shared resource stats
Hetzner CPX11 (Ashburn, 2 CPUs, 2GB, 5.49€ or $6.99/month before VAT)
read: IOPS=36.7k, BW=144MiB/s, avg/p99.9/max 2.4/6.1/19.5ms
write: IOPS=15.8k, BW=61.7MiB/s, avg/p99.9/max 2.4/6.1/18.7ms
Hetzner CPX22 (Helsinki, 2 CPUs, 4GB, 7.99€ or $9.49/month before VAT)
read: IOPS=48.2k, BW=188MiB/s, avg/p99.9/max 1.9/5.7/10.8ms
write: IOPS=20.7k, BW=80.8MiB/s, avg/p99.9/max 1.8/5.8/10.9ms
Hetzner CPX32 (Helsinki, 4 CPUs, 8GB, 13.99€ or $16.49/month before VAT)
read: IOPS=48.3k, BW=189MiB/s, avg/p99.9/max 1.9/6.2/36.1ms
write: IOPS=20.7k, BW=81.0MiB/s, avg/p99.9/max 1.8/6.3/36.1ms
Storage performance is practically always a shared resource, and that's what y'all are talking about here...