No worries about the fees. It has the ability to evolve. Every 3-4 months a proposal with upgrades will undergo a voting phase. All bakers (PoS participants) are able to vote on this to accept or reject the proposal. The source code is written in a purely functional language on which formal verification is applied. Recently the 5 upgrade was adopted, featuring sappling, privacy for smart contracts and more. Adjustements targeting gas costs have already been made in september. So it steadily evolves and takes the tech of other chains if needed.