Currently no country has a well-working solution for that, nor does any company (not even SpaceX themselves)
JWST is a general purpose observatory. It will make significant advances for high-redshift objects. It will not survey large numbers of star for new planets, but it will be able to observe and characterize planets that have been identified by other missions/observatories.
Indeed, larger apertures will be used increasingly. And this megaconstellation actually enables that indirectly. SpaceX is counting on their Starship launch vehicle to deploy the vast majority of their 12,000 satellite constellation, and indeed large launch vehicles (particularly reusable ones) require a lot of payloads to justify their development cost. But large launch vehicles also enable ever-larger telescopes, whose cost is only affordable if those launch vehicles are reusable.
NASA is already buying into it. Here's NASA Goddard tweeting out the larger-than-JWST concept called LUVOIR inside SpaceX's Starship (which again relies on the megaconstellation for demand): https://twitter.com/nasagoddard/status/1116310431969239040?l... ...and yet larger apertures will require in-space assembly over several launches, again only really affordable if there's enough commercial launch demand (i.e. from megaconstellations in particular) to justify these large reusable launch vehicles.
My point of view is that if we're going to be a really spacefaring civilization, it's reasonable that you'll be able to see human artifacts in the sky. Starlink is actually fairly easily stealthed, but other things (space based solar power stations, large space stations, in-space manufacturing depots, etc) may not be so easily hidden. Is the fact that human artifacts may be detectable in the night sky reason enough to disallow spacefaring?
EDIT: Note that the IAU letter is way more reasonable than almost all the media takes on this issue.
IOW, is a speculative, unproven idea.