In many cases, it's mostly just attempting to get the balance right (constant process), info such as this helps.
I do need to work on reward scaling with world level, even if just slightly.
However, like expansion, I wanted some parts of progress to be more long-term.
Originally, the issue was that the tile breakers (used to create space for you to place rooms) were super rare compared to the rooms, so I attempted to slow the rate of gain for rooms to match tile breaker gain.
The next question is if you even have space to use your rooms, without that, you could have 50+ rooms without much use.