What is the future outlook for Cardano staking rewards? (Long-term)

Hello, I understand that the staking rewards decrease over time. A few years ago it was around 4%, now between 2-3%. All good, but I heard that at some point it will rise again due to transaction fees?

That is all I know about this matter and would like to learn more. The questions in my head are like the following:

1. To what percentage will the staking rewards fall before they start rising due to transaction fees?
2. Will the rewards reach zero before they rise again, or will they increase earlier?
3. Will the rewards stay fixed after a certain point and is there a cap on how high the ROA can go?
4. What percentage could they potentially rise to, and in what timeframe?

Again, these are just the questions in my head, which also give you an idea of my limited knowledge on the matter. I of course do not expect exact answers because these things cannot be predicted exactly, but are there any estimates on (some of) these questions or on how staking rewards might evolve?

Or can you recommend any resources for further learning about the future of staking rewards, so I can get an idea myself?

Thanks in advance!