Isn't that the central problem with something like Bitcoin and currencies that can be (read: have to be) mined, though? You gain units of the currency for underpinning the integrity of the system. The average person will never be able to build up a mining system to compete with the likes of China and India where they're mining Bitcoin in farms that potentially devalue the currency every single second.
Edit: For clarity, yes, I understand that there is a finite amount of Bitcoin that can be mined. I'm talking about the value of what's constantly being mined. The US would never use Bitcoin as a currency when other countries already have more of it than we do.
Any currency is only as valuable as the goods or services that they can be exchanged for. The value of money comes from its inherent scarcity as, in the case of fiat currency, only a government or federal agency can issue more of it. With Bitcoin, farms are generating more of the currency all the time. If I generate a ton of Bitcoin but never spend it or use it in exchange for goods and services, I'm simply devaluing the currency that's already out there by making it less rare and, by extension, less valuable.
This may be a misplaced example but I think Star Trek is a decent analogy. Money becomes worthless once replicators are invented in that universe because you can just make more of whatever you need. If China can just mine more Bitcoin than the average citizen of any other country, then China starts to determine what the value of that currency is. It's one of the main reasons why I don't think Bitcoin will ever replace fiat currency. It's already being exploited.
If you mine a Bitcoin and don't spend it, you are making the remaining Bitcoins more valuable (in theory). You have reduced the overall supply.
With Bitcoin, the maximum number of Bitcoins that will ever exist is fixed.
It doesn't really matter who mines them. Of course at the moment, indeed, new Bitcoins are mined all the time, but the timeline for the future is clear.
Whether it is a good thing, I don't know. There are a lot of weird aspects about it.
As for China - sure, some miners will accumulate a lot of BTC. But they can only affect the price by selling or not selling it. If they wouldn't mine the BTC, somebody else would. It doesn't really give them that much more power, except for monetary power.
It's probably true that right now there are several people or entities who could crash the Bitcoin price by simply selling off all their BTC. That's not very reassuring.
On the other hand, such a crash could also be a chance to distribute BTC more evenly. It would actually be in the interest of the rich BTC people, too, as it would lead to more adaption and hence more value and stability.
Distribution is a hard problem.
There are several problems with crypto, but they are also interesting, and smart people are trying to solve them. At least it is fun, even if it is unclear if it will be worthwhile in the end.
Edit: For clarity, yes, I understand that there is a finite amount of Bitcoin that can be mined. I'm talking about the value of what's constantly being mined. The US would never use Bitcoin as a currency when other countries already have more of it than we do.