The willingness of people to save money by doing something in a more economical way can never die .
True, but you can try to stop them from trying to find certain types of more economical methods by using a position of power to dictate what terms the market must operate under.
IT services cost, which are related to IT capabilities, will tend to follow IT capabilities cost.
This means that the IT market (hardware, network etc) dictates, in large, the cost as capabilities cap the max amount of tx/s in a given setup (p2p / decentralized).
In 1995, what we do right now at 3tx/s, with a p2p network that anyone can run on their home PC, would be impossible. Bitcoin would be considered a fancy idea that can't work due to extreme resource requirements. There were no 100gb home disks. There was no 4gb ram to run. There was no 8-threaded cpu, running at 4ghz.
If you take the opposite time direction, in 2035 the cost of running at 3000tx/s or 10.000 tx/s may be the same as it is to run today the 3tx/s network.
More technological capacity => more network capacity => cheaper txs due to better and more affordable technological means.