I think the technology is interesting. I think someday we will be using some kind of digital currency every day, but major innovation needs to happen. Either we need an alternative to PoW (and PoS is problematic) or we need to have
vastly more transaction volume to justify PoW expenses. If Bitcoin could handle a few hundred thousand transactions per second its PoW costs would seem less ridiculous.
One thing I dislike is the ecosystem. It's almost all scams, crackpot projects (unconscious scams?), and pump and dump get-rich-quick shit. There are some people who use it for legitimate commerce or black/grey market commerce (which at least is still commerce), but that's a tiny fraction of it. Most cryptocurrency use is "buy, shill so number go up, then sell."
That's why I tend to downvote crypto posts. If it's related to crypto then it's almost always a shill for a pump and dump. The only ones I upvote are ones with deep technical content that might be of interest beyond cryptocurrency, and that don't seem related to obvious pump and dumps.
The ecosystem is also full of toxic people. Lots of alt-right types, get-rich-quick idiots, and trolls, and I get the sense that serious organized crime has been involved for a while too. It's probably one of the few tech ecosystems where you have a small but nevertheless non-zero chance of being targeted by a mafia hit-man if you manage to get in the way of a big scam.
Lastly, I think the economics are questionable to say the least. Cryptocurrencies almost all implement pop-Austrian ultra-deflationary monetary policies that don't really work in a modern economy and that play a huge role in their attractiveness as gambling and pump and dump vehicles. This isn't a technical requirement though. You could implement other monetary models if they can be coded.
Edit: I get the sense from observing both traditional finance and cryptocurrency that it's really hard to get money to do anything useful at all. It's hard to create a financial system that isn't mostly scams and bubbles. The problem is human behavior as much as conscious crime. If you took the conscious criminals out of the equation you'd still get a ton of bubbles, pump and dumps, and similar nonsense because gambling creates a tighter dopamine loop than useful investment.
Traditional finance is probably like 50% bubbles, gambling, and scams, while cryptocurrency seems more like 99%. Getting to a financial system that's only like half bullshit requires constant vigilance and a byzantine system of regulation and oversight.
