Bitcoin is supposed to be deflationary with a 21m total supply, right?

We all know that inflation in Fiat is like a hidden tax, and some people understand that some don't, a lot of crypto people (by that I mean Bitcoiners) know that.


I can say inflation is bad and Bitcoin with a cap supply will cure that.


So what about cryptos that are inflationary? Or coins that will be inflationary because they are proof of work, or mining that never ends like eth and doge. When will they die?


Unless inflation in Fiat is bad but in crypto is good, doubt it but anyone with an answer could you please share your wisdom.