Ok, who funds it? National Science Foundation doesn't allocate nearly enough money as it is, let alone enough to replace the tens to hundreds of active telescopes producing scientific data every night. And those telescopes are already oversubscribed with people waiting in line for available time. So unless we're slowing astronomy to a halt, we'd need similar numbers of telescopes.
And none of that takes into account that many of these telescopes are used specifically as experimenter telescopes where a given scientist can use their own equipment to perform unique observations that cannot be easily done with space-based telescopes.
It took over a decade to produce the Webb telescope and get it into space, and still is a massive feat of engineering not easily reproduced. We're not nearly to a point where we can just write off ground-based observatories in place of space-based ones.
And none of that takes into account that many of these telescopes are used specifically as experimenter telescopes where a given scientist can use their own equipment to perform unique observations that cannot be easily done with space-based telescopes.
It took over a decade to produce the Webb telescope and get it into space, and still is a massive feat of engineering not easily reproduced. We're not nearly to a point where we can just write off ground-based observatories in place of space-based ones.