You’re using a different definition of inflation.

There are two phenomena we’re talking about here — an increase in the supply of money and the decrease in the purchasing power of money. The term inflation is broadly used to apply to both of these but they’re different which is where part of the hang up is.

In any case, the supply of Bitcoin will continue to increase until it hits 21m coins in approximately 2140, but if it becomes the world’s dominant currency, its purchasing power will continue to increase.

Why should spending and investing be encouraged, can you think of any downsides to encouraging this?

You are the one who described inflation as "stealing from savers, and transferring wealth to the people who are the earliest recipients of the inflated currency". That is talking about purchasing power and not money supply.

There are certainly some situations when you want to encourage saving over spending and investing. However I would argue it is not an ideal stable state. It is more difficult for an economy to grow when people don't circulate money through spending and don't increase future productivity through investing.

The benefit of a central bank that can control the money supply is that you can adjust these things on the fly depending on what is happening in the economy. Bitcoin cannot adjust the money supply in reaction to the economy.

Well, the Austrian Business Cycle Theory [0] has shown that the continuous, never ending increase in the money supply is actually responsible for greatly exacerbating the boom and bust cycle, so there are in fact many losers of this (people who invested money thinking it was safe when in reality it was a highly speculative market, eg real estate in 2007, internet stocks in 2001, etc).

Increasing the money supply ultimately leads to a decrease in purchasing power, which is stealing from savers.

If the market (individuals cooperating with one another voluntarily) valued a continuously inflated currency, then fiat currency will win and crypto will fail. I suspect the market values a fixed or slow-increase-in-the-money-supply version of money like gold as they demonstrated with their money preferences before governments used coercion to stop it, one of the biggest reasons crypto is so popular is because people can’t use gold as money, but governments can’t effectively stop people from using crypto.

[0] https://en.m.wikipedia.org/wiki/Austrian_business_cycle_theo...

Simplify? "Obvious proof is the increase?" One Bitcoin is still worth 1BTC in my books, inflationary dollars' drop in value notwithstanding.

10,000 Bitcoin used to be enough to purchase a couple of pizzas. Now it has enough value to purchase an entire office building in San Francisco. Either the value of Bitcoin increased or the value of everything else on Earth decreased.