There are a lot of reasons that it makes sense to generate more money as the economy expands and more people participate. If you choose not to expand the money supply, you've created deflation. Yes, it does increase your buying power. However, it also slows down the economy as people tend to save their money thinking they will get a better deal if they just wait until their buying power increases further. This is why the Fed and monetary policymakers around the world target small inflation rates - to give people incentives to stay active in the economy.
At a certain point, you also reach practical limits of the money supply. If I want to build a house and I need to borrow money, if there is a hard money system if you keep a hard money system and never expand the supply there is a real chance that there literally may not be money available for me to borrow. This type of situation happens in the real world today at the level of international trade - it's called a dollar shortage. In a way, most countries of the world back their currency with USD as a sort of hard currency. At least, a currency they don't have control over. It's a fairly abstract topic, but I think this article explains it reasonably well: https://mises.org/wire/why-world-has-dollar-shortage-despite-massive-fed-action.
When you say that the system is rigged, I'm not sure who you think is rigging it or for what purpose. Goods have gotten cheaper. If you look at a price chart of typical consumer goods, you'd see that many of them have gone down over time when you look at it in terms of decades and centuries. If you're looking at the past year, sure things have gone up. But if you looked at say 2014-2019 you'd see many prices decreasing over that time.
Fiat currency's value is not determined by government's decree - it's determined by the people who use it. Look at Zimbabwe, Weimar Germany, or dozens of other examples - the government didn't say "Our currency's value should decrease to the point that it is worthless." The people said that - they didn't accept that the value of their money remained the same after all the printing. They could have. The value of the US Dollar and the Euro sometimes go up on their own too - governments would prefer they didn't get too strong to help international trade, but they don't get the choice. If the people said they don't think there is any value in the US Dollar, government decree would not make it valuable. Currency of any kind is only valuable because people think it's valuable. The only power the government has is to redirect its people to say "this not that" and that only works if the people go along with it. Just like Bitcoin. It only has value because people think it has value. And the minute people stop thinking it has value, it's just a fancy computer program.
I won't claim to be an economist, but I have read enough to know these matters are not settled issues and that there are critics on all sides. Should we employ MMT (Modern Monetary Policy)? Is a debt based economy healthy long term? Is the fractional banking system broken? Should we have a full reserve monetary supply? Should currency be backed by hard assets? Should a deficit be avoided or is it healthy? You seem more educated on the subject then I am and I suspect you would have reasonable answers to these questions.
Regardless of the above questions, I am happy to agree that the fiat system "works" for the most part. People can invest, take out loans, save, and spend fait easily. And all of this operates under a decent fraud protection system. I will submit all of that.
But there remains a hole that I believe only bitcoin can fill. I would be interested in your opinion on the following:
Our economic and banking system does not allow you to save value in USD denomination. In that sense, I believe it is broken. For example:
In 2021 Bob works and earns just wages of $5. $5 is the current cost of a hamburger. He decides to forgo lunch and save his money for future Bob. He deposits his $5 in the bank. Bob expects some return for allowing someone else to use his money. In 2031 Bob withdrawals his $5 from the bank and heads out for lunch. Much to his surprise, not only could he not buy a hamburger with some change to spare, he could actually only afford half of a hamburger.
So if you cannot save and protect buying power in USD denomination, what is the solution?
Bitcoin. It is the best sound money ever created by means of these properties. No other financial instruments meets this criteria.
Durable - they are digital and not physical like gold
portable - can take anywhere in the world and send to anyone
divisibility - You can obtain as small as 1 satoshi. There are 100000000 satoshis in a bitcoin
uniform - blockchain ensures all bitcoins are the same and cannot be duplicated.
scarcity - 21 million fixed supply
I am not suggested a crypto takeover our banking system. But I am a huge proponent of bitcoin as an option for people worldwide to store their hard earned value. It has the power to liberate many of the unbanked in the world and offers freedom for people in countries with awful economic environments.