That's why we have things like paypal and temporary virtual credit cards.
Many kinds of fraud attack the fallible human element, not technology. And blockchains cannot change that, as you can see with a glance at crypto news.
Trust is a short-cut for the complexities the physical world presents. But in a purely digital world you can build things that doesn't NEED the short-cut. And that's a new capability. It let's you build things not possible before. DeFi exists because trustless transactions are possible. Not everything can and should be trustless, it's just a tool not a new society. But it's SUPER useful.
Sure, but it also makes it not an answer to the question which was asked.
And just because the technical solution to a technical problem might not be (/isn’t) a good/practical solution to the practical problem that the technical problem is inspired by, doesn’t make interest in the technical solution illegitimate.