For now its supply still inflates by ~1.7% a year.
Neither you, nor I will live to see that moment when the last bitcoin will be mined (as long as miners keep mining in our lifetime).
Bitcoin exists as an option to a lot of very inflationary assets (currencies which not that long ago almost reached 2 digit inflation rates) and having different kind of assets should be welcomed in my opinion, as it seems like a good way to diversify the risk you can't "straightforwardly measure".
I like to hold at least one asset for which I can almost guarantee a supply/emission won't change... better yet I can trustlessly verify it. If these propositions are not attractive to you or others, they don't have to acquire this asset either, it is completely opt-in, unlike the fiat money which your government forces you to acquire to pay their taxes.
No, we don't need some grand wizards in an ivory tower to finely tune the amount of money in the economy, that idea is absurd. The economy has worked fine for thousands of years before they started doing that. In fact, since they started doing it we've seen ever growing boom and bust cycles.
Personally, I don't think a deflationary global reserve currency is the precise answer, but I do believe that these experiments in monetary governance (like Ethereum's burn and mint model) will allow us to move closer to it.