I had somewhat a similar experience in a previous job. Automated a lot of stuff to speed up our workflow. Never got anything material out of it (bonus/raise, etc). The reward was an expectation to increase our output ("Now that it takes half the time to do X, everyone should double their output.") The other reward was maintaining my code while expected to double the output. At one point the manager made it clear I would not get a promotion based on this.

I left, and in my next job I tested the waters a little to see if they'd value such contributions. They did, and so I happily continue to make them. Had they not, I would have stopped quickly and moved on to another job. As an engineer, my job is to solve problems that need to be solved. I could be like everyone else and just go along with it (not solve them and maintain the status quo), but that's not why I became an engineer.