After halving, it will be reduced, therefore, transactions can become cheaper. It will happen each time after halving.
I don't follow your logic.
Fees are meant to compensate miners for the lack of block rewards, which means that the lower the block rewards are, the higher the fees will be. The block size won't likely be getting a bump in the forthcoming years, but the demand for it will continue to grow due to more user adoption, so you better expect a significant increase in transaction fees.