A huge percent of people in the cryptocurrency sector stores their crypto token on their exchange account which is why they easily lose their assest due to exchange attacks and the likes. If this exchanges out there secure their platfrom with high end security as well as a reservation for safu when an attack is launched to their exchange to help user recovery their stolen funds, people won't be bothered about saving their assets on exchange. But regardless of this, it is expected for everyone to always keep a huge amount of their holding in their blockchain wallets.