Coal is a bad analogy because coal also generates a lot of energy and has uses in chemistry and metallurgy, and those things create real value.
The problem with coal is that its externalities are not properly priced in, making it look quite a bit cheaper than it actually is. Much of its cost is being placed on a hidden credit card with an unknown interest rate. If all externalities were priced in coal would probably not be competitive except in places with few other good energy options and in roles where it's hard to replace like bulk virgin steel production.
Crypto has few real value-creating uses outside the original core use cases of easier international wire transfer, some utility in areas without functional banking, black/grey market commerce, and hobbyists/techno-nerds who use it because its cool. Those use cases are real but they are also the use cases that existed in 2008-2009 when Bitcoin launched.
Web3, ICOs, and DeFi all seem to be almost 100% gambling and scams. Every few months I go looking for systems and use cases for crypto other than the original ones mentioned above and all I find is gambling and scams.
I don't think crypto will go to zero, but I think its actual value is very far below its current price. FOMO marketing for various forms of web3 and token shonk is getting increasingly shrill and desperate, which is not a good sign. If I had any of this stuff I'd sell.
Of course remember: it's very hard to call the top of these things. They almost always go higher than anyone expects. Sub-prime mortgages kept going far beyond what anyone thought possible. Regardless, you don't want to be a bag holder when it eventually does crash.
The best way to win in a casino is not to play. The second best, if you've played, is to quit while you are up and ignore the fact that there is a chance it might go higher. Here's some good old fashioned Native American financial advice on this topic:
https://www.youtube.com/watch?v=KXbDB3uEltY
You aren't special. Someone will win big in the casino, but it won't (statistically) be you.