Space-based solar power (SBSP) has three advantages over terrestrial solar: flexibility, footprint and theoretical efficiency.
The classic case for flexibility is disaster zones; it's easier to set up receiving meshes than build new power plants. The problem is humanitarian crises don't pay. The real sell is military and mining. Beaming power to remote operations simplifies logistics.
Footprint is minor, but worth mentioning: the receivers for space-based solar are smaller and could be laid over e.g. farmland.
Last, but not least, the atmosphere absorbs a lot of solar energy. In this model, the space-based rig is a lens, converting the well-absorbed frequencies that generate power into microwaves to which dry air is more transparent. If you can get a focussed beam, a SBSP rig could also be placed far enough out that it's less subject to Earth's day-night cycles. These factors boost its theoretical efficiency.
I haven't run the numbers for several years. But they only become compelling if you have ISRU and in situ manufacturing of panels. I don't think SBSP is a beachhead market for asteroid mining. But it's feasible if we have it.