francopoli to back me up 'cuz that d00d has forgotten more about telescopes than I'll ever know and am_Unition because he does space observations for a living and stuff but
adding scopes up optically doesn't gain you that much. I mean it sort of does but at that point you're basically getting non-visual data in the optical wavelength, it's not like you get a better photograph out of it.
Deformable mirrors and laser guide stars have basically allowed an entire generation of telescopes to stay relevant. You can virtually eliminate atmospheric perturbation with one. I went deep down the rabbit hole on this one because I figured if I was able to cobble my own MEMS array I could spy on spy satellites and shit which would be SUPER COOOOL but then I got to talkin' with the guys at Palomar and when you're talking "guide star" and "atmosphere" you're no longer talking "eBay lasers" you're talking "notify the FAA when you turn it on lasers" and that was about the time I realized that optics is kind of a settled science and that the engineers are applying materials science and state-of-the-art processing and manufacturing techniques faster than you really hear about as an amateur.
I mean obviously big damn mirror in outer space is always going to win. People have been suggesting telescopes on the far side of the moon for 60 years or more. When you say "things are going to be super-great if we can ever put a 20-foot mirror out there at like, Lagrange 2 or some shit so that the thing is completely isolated" the astronomers will say "it already has a Twitter account." And when you say "asynchronous viewing" they say "you mean like when we look at something in December and then again in June so that our light-gathering is 2AU wide?"
The black hole "photo" wasn't a triumph of imaging, it was a triumph of DSP. The signal they were working with wasn't anything new, really, it was the gob-smacking amount of post-processing necessary to cull the noise. From an imaging standpoint, the JWST is gonna be sumpin' else.