What makes you think the problem is money and not materials science? We have no substance suitable for the cable. The closest we've come is various nanofilaments that we can perhaps produce in centimeters, not kilometers.
I recall excitement that https://en.m.wikipedia.org/wiki/Colossal_carbon_tube were just the ticket. But since there has been zilch published on them in the last 14 years, I'm guessing the original work couldn't be reproduced.
I agree that the problem is materials science. My point is how much money is actually being allocated towards that vs sending stuff in space, to what end?
I don’t follow material science stuff super closely but as far as I’m aware the investment is orders of magnitude less than propulsion and other tech.
Then again these things just take time unfortunately
