The single largest hurdle to this technology has been high launch costs. Microwave emitters, waveguides, high-efficiency rectennas, and all the other stuff has been old-school since the 1970s -- and we have learned a pretty good chunk about 'assemble stuff in space', too.
Once again, it is SpaceX to the rescue. Our human settlement of (& enterprise in) cis-lunar space is all fundamentally bottlenecked by launch costs, which SpaceX has been relentlessly driving down. When Starship becomes available for transporting cargoes -- probably sometime in 2023 -- launch costs will begin to drop even further. With Cheap Access To Space (CATS) expect to see a large jump in universities and businesses trying all sorts of new things -- including space-based solar power.
I am still wondering what "unintended consequences" we might discover when we start exposing large segments of human society and the natural ecosystem to microwave energy transmissions. Some of the things envisioned, such as actually powering aircraft with the absorbed energy from space radiators, sounds like it should cook things like a microwave oven. Yes, I know that those ovens use a frequency tuned to be best absorbed by water molecules, but I also remember that service men at the DEW Line early warning radars used to stand in the radar beams to keep warm, and that was only detection level energy transmissions.