How do you explain "FTX-esque" sites and their risks to friends?

Short story: explained little bits of bitcoin many times to friends over a five year period. In 2020 about 80% of them started trickling spare change in via various exchanges and then moving bitcoin onto their hardware wallets. Success?

Fast-forward and I just learned the one who goes in hardest with EVERYTHING in life has been talking to a "crypto friend who is super paranoid so would only trust the safest methods" - he's put his faith in a website that seems extraordinarily close to FTX - no keys, posts about funds being lost, no reputation, no proof of reserves etc. He's also been leaving all his funds on it because "trading is so easy" - that's the bit that set off alarm bells.

I only lightly tried to explain so far - I don't want to go in completely negative and frustrate the guy into stubbornly continuing because his weird "crypto friend" seems to have convinced him pretty strongly that he should be using this super simple app/website to trade and make money. It's sad but it's how most people still see the space; a quick money multiplier.

What would your points of reference or important pillars of bitcoin be, to help explain to a friend that they should be a lot more cautious of the tool they are using?