The reason for inflation is, that this incentivizes people to spend. Because in current economic terms, spending of an economy defines its success. But in such a scenario, you have 2 ways to acquire money. Provide value, or just print money. Therefore providing value is not incentivized anymore, because printing is easier. Principle of least resistance.

But in an economy, where there is fixed supply, your only way to get money, is to provide value. Therefore, you are incentivized/have to provide value. And if you want to provide value easier, you have to innovate. So a fixed money supply is incentivizing innovation as well.

Which economy do you want to live in?