Can you tell more about their subpar latency?

I've been using Hetzner for many years, both personally and for business use, and I've not seen any noticeable issues regarding the latency.

Granted, my use cases are webapps/backends that are not particularly latency sensitive, and are primarily used from a few European countries.

For what's worth, I've seen cases where download speeds from Hetzner are considerably higher than from AWS eu-central-1.