All true! And mostly better for the ultimate purpose of a telescope, which is why we prefer to put them in space. However none of those advantages offset the

All true! And mostly better for the ultimate purpose of a telescope, which is why we prefer to put them in space. However none of those advantages offset the greater cost, e.g. your "expensive structure to keep the mirror from deforming under gravity" is simply a steel scaffolding. Admittedly to higher precision than an office building, but not extraordinarily so. I think perhaps you are not respecting the challenges of space and the cost to operate reliably in it, even if launch costs were zero and mass unlimited, so I'd encourage you do do a little more research.