I am well aware that other  blockchains  can also change their reward functions.
The point is that you promote your blockchain here with completely different tokenomics than you have implemented. You didn‘t implemented a max supply and your halving cycle was 4200000 blocks if i am correct. With a block time of 120 seconds it would take 15 years to reach the first halving and 42 million coins would have been mined.
And with your new half baked reward function you will also still get more than 21 million coins.