This could be so hilarious but I just need you to contribute.

If someone has two mobile phones, deciding to use one as a mobile wallet. To me, this is a good idea as one of the phones can be useless. And having in mind to use it as wallet and putting these in consideration.

Having back up of his private keys or seed phrase.
Not using it to go online but online while making transactions
Still install anti malware against malware

So, he use the phone only as wallet and for crypto transactions. So, what do you think. Is this a good idea?