I mean we can't really say it would be fully safe from any form of attacks if hackers can simply use other means of attacks like phishing, etc. I believe it comes back to what is your goal and how familiar are you with crypto wallets etc. I don't seem to see your answer related to this question. It sounds like you want to make crypto transactions regularly but you don't need mobility, so using a phone is probably not necessary. On the other hand, you mentioned a cold wallet, which doesn't sound like what you described above.

AFAIK, just opening and using a wallet on your phone is not going to lose you money. Most hacking cases happen from storing your seeds online, phishing, etc. A wallet hack due to software/server issues like what happened with Atomic is rare iirc, and you should be able to avoid it most of the time as long as you don't use closed-source software. CMIIW.