I think its total mirror area is more than that of all existing (largest) professional reflecting optical telescopes combined
39.3m aperture, mirror area scales quadratically with that https://en.wikipedia.org/wiki/Extremely_Large_Telescope
https://en.wikipedia.org/wiki/List_of_largest_optical_reflec...
https://en.wikipedia.org/wiki/List_of_large_optical_telescop...