It seems like you're conflating the value of crypto with the recent blunders of crypto-focused businesses. The fundamental value of cryptocurrency is being able to self-custody tokens of value without relying on any other mechanism besides the proper functioning of the blockchain and its respective rules. What we're seeing here is a lack of clarity/regulation amongst world governments on how crypto and the businesses that manage them should be treated.

The promise of DeFi has a higher barrier of entry for those unfamiliar with the technicalities of interacting with decentralized systems, but they generally have more transparency in management of funds than crypto-centric businesses. All code running on the blockchain can be audited and so can the funds held within smart contracts. There are plenty of valid criticisms that can be made of various cryptocurrencies with those models of on-chain finance (and even with the value of cryptocurrencies themselves), but criticism of cryptocurrencies deriving from bad businesses that manage them shouldn't be one of them in my opinion.