In theory having fewer repeaters improves latency, probably in the range of 100ns per repeater. I don't know how much of a practical effect that has, likely very minimal with modern implementations.
Either way it's more sensible to build high throughput microwave networks given the tiny amount of shortwave bandwidth we have.
Shortwave radio can be transmitted around the curve of Earth by ionospheric reflection and refraction so fewer repeaters are needed. This allows crossing vast oceans where microwave infrastructure might not be possible.
As you say the downside is available bandwidth and throughput.