ROI Coin is not worth mining.
1) Staking coins come out of thin air dont reduce the minable coins (maybe because of the copycat failure from the other coins of the delevelopers, which resulted in negative amount of coins once you staking reaches the hardcoded limit).
2) (offline) Staking is more profitable than mining. Do your maths how many coins based on your hashrate do need to stake to receive the same amount.
3) Because of high inflation and unlimited coin supply from staking it will very difficult/ impossible to mine profitable (even more in the long run)
4) ROI dont have any benefits itself - only high staking rewards for long term holder (which increses the inflation even more)
I dont agree with you the mining reward and interest rates will decrease each year, so after 5 years after the ROI coin is circulated to world.
you cant mine much to be top of all. its a good concept and pure Banking system where you get ROI coin interest for fixed deposit like any other fiat currency bank..