Mirror size is the issue - until we can easily manufacture huge, incredibly precise mirrors in-situ, space based will never replace ground based astronomy.
It’s not manufacture. It’s assembly. And I think astronauts are faster and cheaper than robots for in space assembly. Or they will be once Starship is operational. NASA did a ton of work in EVA orbital assembly with Shuttle (and still chooses to do exterior work on ISS via EVA and not purely robotically) but it was always like 10 or 100 times too expensive. Starship ought to change that. In addition to its 8m diameter payload bay.