Storing your main asset and portfolio on a smartphone is a big no. You shouldn't do that, even it is your main phone. What you must do is to have your phone dedicated only for crypto because I think that you're able to afford that. Because using your main phone, it also means that you're going from one point to another and you're going places.
Not only are you bringing your phone from one place to another, you are also using it for different purposes which may expose your phone to different risks. Using different social platforms, downloading different apps and software, you never know what kind of risks may those things bring.
Navigating through links may also endanger your device so it is much recommended that you only use your mobile device for crypto alone.
I think there are mobile phone users who doesn't like to bring their mobiles anywhere they go. They can also have more than one phone and they just leave the other in their house as it stores important files. Phones now are still very secure. On top of that, we can put a passcode, so that once we accidentally lose it or it was stolen, it won't be opened immediately and then we can remove our accounts there remotely. If we are talking about malwares and viruses, as long as your phone is not old, it will still receive security patches, so that you are safe from them. They might only be an extra-layer of protection because we might still install the viruses manually.
Phones now are very smart that they can do almost any things that we can think of or a computer can usually do before. This is the reason why people are using it for different purposes. If we are really serious about the security of our cryptos, then it's better to just buy a hardware wallet for them (not phone). You can also save money this way and it gives more sense. As long as we are visiting the known and trusted sites and we already bookmark them, we should be fine. So I won't be paranoid as that can only make us crazy.