Max IOPS without paying for provisioned IOPS is 3000 (gp3 stock setting). Much lower than other providers and will cap your database performance. That's combined too, 1500 read and 1500 write. Throughput is 125mb/s.
Hetzner gives you 45k if memory serves, vultr gives you a ton, akamai cloud gives you at least 40k and some instances give you 125k. With throughput in the >3GB/s range.
Provisioned IOPS cost thousands per month to reach these levels via io2 volume. Io2 is capped at 45k if memory serves unless you have a bare metal instance. Which is a whole new pricing tier I didn't investigate.
I believe it is cheaper per IOP to go wide with gp3, complete with additional compute, than to provision io2. Which really kills the whole "go tall not wide" architecture strategy.
Big price bump with dedicated vCPU encourages wide rather than tall also. You can buy a ton of compute for that $2/hr fee.
Moral of the story. Don't try to go tall on Amazon.