Most platforms have better security than most users today already.
There is this one particular phrase that always comes up in most of our discussion concerning Bitcoin, and this is "Not your Keys, not your Coins." Thiiss very prrinciple is taken seriously by many of persons her, but I noticed that there are still a good numbers of Bitcoiners both the experts and even the newbies that still relies on custodial platforms. A fellow Bitcoiners once told me that his preference for custodial platforms is as a result of "it's easy access and convenience and even claimed that it had a stronger security measures." But most of what he said don't really add up if we take a look at the collapse of FTX in 2022.
With self-custody, the responsibility is entirely on the individual no doubt, but if you control your private keys, you control your Bitcoin. But once you hand that control over to custodian platform, you are simply taking that trust and handing it over to another and the case of FTX and many others has shown us how bad that can eventually turn out.
We are talking about a fairly unregulated and uninsured platform though. Things will get better over time as bad actors disappear and regulations become better, but nothing will ever beat an educated user who does self custody. That said, such users are very few.