I know a handful of people who benefited a lot from Bitcoin by just speculating with it. They got wealthy, some even rich and now they have much better living standards. That group fits into the niche that were quite well "served" by Bitcoin.

Just pointing out that "scammers and criminals" is clearly not the only ones benefitting from Bitcoin, and I would suspect it is also minority.

And where did that wealth come from? Other people's trading losses.

So now the stock market is a scam too?

Stocks pay dividends. Cryptocurrencies don't.

Commodities can be sold and consumed for some real economic purpose. Cryptocurrencies can't. It's like gold except you can't see it or make jewellery from it or use it for anything.

I made no comment(s) on your above mentioned points. I was replying the assertion that "trading gains are someone else's trading loses".

It's an arithmetic consequence of there not being any intrinsic return. The money won from cryptocurrency trading can only come from other traders, because there are no coupons, dividends, or physical deliveries.

The stock market is not because good companies really do become more valuable by doing real work. It’s not zero-sum.

I don't know why this has been downvoted, it's basic economics.