How do you even tell if crypto platforms are legit anymore?

Hello everyone, I’m 49 and I just started exploring crypto for some passive yield. I almost fell for this sketchy crypto platform yesterday and I’m paranoid about everything right now… I received a spam email about some DeFi yield thing promising 20% APY on stable coins, a decent looking website with charts and testimonials, even a whitepaper that sounded legit at first. Domain was like platformname dot finance, registered recently but they claimed partnerships with big names like Kraken and Coinbase tried googling it to find some reviews on medium sites but nothing on coingecko or defillama, which made me pause. Signed up with a burner email and they asked for wallet connect right away to deposit USDT for some bonus, no KYC yet which felt off. Also the twitter had like 5k followers but mostly bots from what i could tell, posts were generic pump stuff.

I backed out and didn’t connect anything but now I’m wondering whether i dodged a rug or am i just paranoid. I’ve seen those bridge exploits like that Kelp thing where everything looked fine until millions gone.