I think this 'not your keys not your coins' mantra has some merit (in the sense that people should be aware of any risk) but it's a blocker to adoption and scares newbies from getting involved. The future of crypto is not about appealing to a few people who stuff cash under their mattress because they don't trust banks, it is going to depend on the crypto space creating further protections against fraud (rugs, hacks etc.) to ensure crypto and defi isn't a scary place to be.