Most people now are using Centralized exchange to receive pay and trade.
Anyone using a custodial wallet to store their funds doesn't understand BTC and how it should be used, not to talk of the risks in using a custodial wallet to store funds, i guess people do not just learn.
Many people know about it but you can’t convince all. Some people are use to been negligence of their funds, while some see it as a bearable risk to be taken, it is definitely a risk not to be taken. It doesn’t spell well about a bitcoin professional, or someone claiming to know well about bitcoin. Prevention is always and will always be better than cure.
those who still hold Bitcoin and other assets on exchanges are beginners. or maybe there is a need for trading in a short time. I'm sure to this day there are still traders who do it. but those who are experienced will of course withdraw their assets to their personal wallet after completing their needs on the exchange.
now I use Electrum on my PC. It is quite light and very easy to operate. I have tried several wallets but I think Electrum is the most suitable for me.
but I'm sure some people still use wallets such as Trust Wallet or Safepal which have a relationship with an exchange.