So these are tiny and cheap so you stagger the launches so they can relay their data back to earth. Each one could be within a few 1000km of the next one.
It’s still 400,000 times less distance to transmit a signal so it would help.
I guess you build in redundancy, but it's not obvious to me that the added complexity - probes have to send and receive instead of just send - is worth the benefit. I really have no idea about this space though.