Yes, agreed. In fact, the first example I can think of is the Michelson stellar interferometer at the Mount Wilson Observatory, which was in operation in 1920.

Yes, agreed. In fact, the first example I can think of is the Michelson stellar interferometer at the Mount Wilson Observatory, which was in operation in 1920. However, there has been a major push recently to circumvent the limitations of optically connecting the telescope arrays; there are a few different approaches, of which I'm not aware of any fatal flaws. Seems likely it's a matter of time and physics and engineering; very difficult, but achievable. See for example: https://dspace.mit.edu/bitstream/handle/1721.1/51042/Tegmark-2009-Fast%20Fourier%20transfo.pdf;sequence=1 https://dspace.mit.edu/bitstream/handle/1721.1/51042/Tegmark...