A scenario like that typically goes like this:

- Client orders an analysis of something. They want all corners covered, and because they'll use it as evidence/argument/pitch or whatever, you're likely working on a tight deadline.

- You (and others) work tirelessly through the nights, pour hundreds of hours into the analysis, do get it finished before deadline. Everything needs to be perfect and bullet-proof.

- Client is presented with the delivery, skims through it, and thanks you for the work.

- The client changes their mind / abandons it all-together.

Those projects rarely feel rewarding, as you're mostly just fighting the clock, and doing lots of boring routine work. And when it turns out that you and your team are the only ones that will ever read the analysis, that kind of just makes it feel useless.