While I agree with the majority of things you said, let's not forget that not everyone is able to use cold wallets, DEXs, and other tools that require a certain knowledge because just one little mistake and you can lose everything. With this I'm not saying that CEXs are 100% safe but for the average Joe they work just fine. If CEXs didn't exist bitcoin would need way more time to spread and in the future they will likely succumb to DEXs but, in my opinion, for the moment we still need them since we need more adoption.