For Voyager-like mission profile building useful network of such data relay satellites/probes would be prohibitively expensive. For missions where that makes s

For Voyager-like mission profile building useful network of such data relay satellites/probes would be prohibitively expensive. For missions where that makes sense (mars probes, STS, ISS and IIRC even original Apollo moon landings) relay satellites or even networks of them are/were used. To some extent for such constructions to be useful it has to be constructed of satellites that orbit something which is near to target of the probe, which is impractical for probes that are on highly eliptical orbits around sun, not to say probes that are on exit trajectory like Voyager.