Just put a 5G tower on the radio tele... nevermind.

Data rates are high for the particular types of astronomy being done today because they are the cheaper capability. Adding new electronics to existing telescopes is less expensive than building a larger dish. But any astronomer would trade those date rates for the greater sensitivity/resolution and decreased noise of a massive space-based dish.

The stream is also in one direction.

I suspect an optical (laser) emitter could transmit either directly to Earth or to a retransmission satellite at GSO that already has a beefy radio downlink, and also serves as a regular comm sat.