Do the people opting in truly appreciate that one software bug could empty their account?

Most all of the people in defi do, yes. It's happened a number of times now, so you'd have to work pretty hard to understand enough to use defi but not be aware of the risks.

People who interact with non-bitcoin crypto tend to be a lot more knowledgable about the tech and its implications than an average person. So I would say the answer is probably yes.

Ah yes. All the geniuses that are around the crypto subreddits for example. Definitely Turing award level.

I didn't say they were geniuses, just that they were more familiar with the tech and its implications than the average person. Smart contracts have been around for a while and we basically know the scope of the catastrophes that can result from bugs in smart contract code. The DAO hack was years ago. This is not a new problem space

This is an irrelevant point and borderline strawman. Considering the environmental impact of proof of stake blockchains, everyone is impacted whether they use crypto or not.

The environmental impact of proof of stake blockchains is virtually nonexistent.

It's mandatory in El Salvador. That alone is a QED. However, I'd highly recommend listening to any of the thought leader talking heads.

its mandatory _for businesses to accept BTC_ not for the populace to use it.