Agreed. I suspect that the impact of added Hubbles would be roughly linear in the number of satellites for at least three or four more satellites.

The bigger question is whether the requisite resources could have a larger combined impact elsewhere by delivering similar advances in astrophysical missions, for which I suspect the answer was correctly judged to be "yes".

Hubble’s replacement, James Webb, could offer us an opportunity to have a second space telescope.

We just need to figure out how to repair the Hubble.

And I really fail to see why we build ONE James Webb. What of there is anomaly at launch? Why not build two? If one fails, we have another. If both launch, we have two telescopes! (Well, I don't know how difficult to have to instruments bobbing around L2 point).

Most of the price of JW is research and development anyway. It will not be 2x the price, it will be much less, so even if we ignore the possible scientific output, from a purely financial perspective two would be a bargain.

I just don't understand why we build one JW, and one Hubble, but we can afford 12 KHs and god know how many other spy telescopes...

First rule in government spending: Why build one when you can have two at twice the price?

If only this was true.

A relevant Contact quote, on the topic of Space?

nicely done.

Its not a replacement . Its a successor

Hubble will be gone in 5-10 year.

Whenever it breaks it’s done.

Call the James’s Webb whatever you want. The point is that it would be useful to have both for decades

James Webb isn’t a spy satellite chassis. The Vera Rubins telescope is though

I think the James Webb focuses on the near infrared spectrum?

The deep field images are not a significant fraction of the total scientific output of Hubble.

Nope, they are the icons of the project. Images from the edge of reality.

They significantly impacted how I grew up seeing the universe though, and I’m sure I’m not alone on this.

In that case, you're arguing that a greater fraction of time with scientific instruments should be devoted to publicly consumable results. That's fine; I mostly agree. But that's not the claim under discussion, which is whether we would have much more total scientific impact if we had many more Hubbles.