> for a single successful research grant, hundreds of days might have been spent, purely on the acquisition of funding.

I'm a former professor who has written many proposals and won some of them. I've reviewed many more.

I did a lot of thinking and research when writing proposals. In a proposal, I tried to clearly explain the state of the art and how it could be extended, what resources I would need to do that, and how that work could be structured to make success more likely. I might even do a pilot study to show that the key idea is promising. Note that 'how to extend the state of the art' can be a seriously creative inventive step, or it could be the obvious next thing. But creativity does happen at proposal stage, and it certainly factors in my reviews of other's proposals.

My point is that writing proposals is not entirely a waste of time. It's a bit like writing a movie script. It's not a movie, many scripts never become movies, but for some movies some of the best ideas were in the script. Same for proposals.