Sadly, there are still people that keeping their funds on exchanges so that they're ready to sell them asap. But most of them are just keeping it there for storage purposes and they can't determine whether they'll sell or not when the bull arrives.
While some may think that they're wise enough to keep it there because of the current high fees again, it doesn't makes sense if you have no intention of selling.
That's a stupid excuse for anything that are keeping their Bitcoin on exchanges, it takes only few minutes to send your Bitcoin from a hardware wallet to a exchange, it's not a demanding work at all, I believe the reason why some do this nonsense is because they trust the exchange more, if something goes wrong they can blame the exchange. While some may think that they're wise enough to keep it there because of the current high fees again, it doesn't makes sense if you have no intention of selling.
Yeah it definitely is exciting but this over excitement of holders not patient enough is what has caused drastical increase in fees. Take a look;
I've checked the fees as soon as I've seen the price increase and again, it's high. It's just the way we all get used to banking system, we give our money to them for safe keeping and if something goes wrong we blame it on the bank, many people would rather blame something else than blaming themselves, that's why many people don't accept mistakes as their own.
Sadly many people are still like this today, claiming ownership themselves is not in their blood, non-custodial sounds scary to them, they will rather leave the assets in the hands of centralized exchanges, mind you, not all of them, some left those funds on exchanges for trading, it's not all they have, it's just the amount they can afford to risk in the hands of CEX.