For ponzi-schemes, you have to look at the crypto industry's lesser known feature: Tokens
Long before NFT's, companies have been manufacturing systems to create "tokens" (usually utility tokens) and trying to sell them to other people. This usually happens through crypto conferences, crypto meetups etc. Typically, the plan is to convince people of their impending value growth by going on a long complicated sounded explanation of how tokens are earned and how many people are buying into them, and then get that person to by a bunch of cheap tokens. The promise is that they can then sell them to others to make more money, or (in quite a few cases), sell tokens to someone who will sell tokens and give the initial seller a small percent... and so on.
Bitcoin did not start with fiat-investment opportunities, but with the way the entire crypto market is operating, that's the goal now: creating investment opportunities. It's proven to be a very effective means of making fast-money, so there's no incentive for the market to move away from pushing crypto as an investment hole rather than focusing on value control and stability to make it a more accessible form of currency. It also makes me wonder about how functional a lot of these coins even are in terms of utility. How many stores will accept every single kind of crypto?
And nobody wants to talk environment... but it's a really huge point to bring up, especially now that the environment is worse than ever. I've really dug into the impacts on other posts, but I try to at least mention it because this is the one big aspect outside of the "currency" itself that actually impacts people who choose not to participate. The GPU shortages, the giant mining farms, growth-driven-proof-of-concept-difficulty-increases, etc. I get it, they're working on something better than proof of work in terms of energy consumption. But look at how many of the damn things exist! And since all crypto currencies work alongside fiat, it's not like we're replacing traditional banking.
Sure, the energy consumption and carbon dioxide output is roughly ~50% of traditional banks, but unless everyone suddenly decides that they don't care about their fiat investments, that output is just going to grow alongside traditional banks
you have to be delusional to not objectively assess the state of gpu prices and the environmental impacts as "bad"
https://priceonomics.com/how-has-cryptocurrency-mining-influenced-gpu-prices/ here's an interesting bit on the prices
environmental impacts are largely: Carbon dioxide output, resources required to accommodate expanding blockchain, increase in proof-of-work requiring even greater resources and even higher carbon output, greater strain on gpu demands etc. then take those reasons and consider ever single crypto with these issues
all in all, you could say that those things are all bad