I've kept some of my coins on Binance for like three years and I haven't lost any. However, I knew what I was getting myself into by doing so, they could've locked my account for any reason and could've ended up losing my assets. I think some of us are addicted to convenience even we know the risk. Those who stick to " not your keys not your coins " rule are usually people who've had a bad experience and have lost a lot of money by trusting a third party.
We like being convenient and that gives us confidence that our funds are safe in an exchange like Binance. But we all know that there should be some thoughts from us despite having that trust and confidence from them. If we have no intention of trading there for so long, it's better to keep the funds into a hardware wallet.