Many countries have thought to change currency into bitcoin because the government thinks bitcoin is more related stable than USD. because the reality, USD is not have something great if their foreign policy isn't great in the past. The powerful country is just running their greedy for self-benefit. Now, they begin to turn to bitcoin and look like started to control the bitcoin inflation, so what you think if bitcoin inflation is wilder than fiat?
Bitcoin has inflation that decreases over time. This is implemented through a mechanism such as halving.
In addition, Bitcoin inflation is decreasing due to the constant withdrawal of coins from circulation. The withdrawal of coins from circulation occurs due to the loss of access of holders to their wallets (due to death or negligence). Fiat currency inflation depends on the economic situation in the market and on the actions of regulators (for example, Central Banks or the US Federal Reserve).
The inflation of fiat money and Bitcoin is very difficult to compare with each other - they are different concepts.
But we can say that in the long run, fiat currencies are an inflationary asset, and Bitcoin is a deflationary asset.