So far I use Android but it's still safe, I've been storing assets in bluewallet and eletrcrum wallets for years without any problems. Actually there is no influence between Android and OS as long as you take good care of it, your asset data will be safe. Don't try using a smartphone, don't click on unclear links, when installing any application on your phone always pay attention that the application is correct, not a fake application.

The point is, storing or managing a wallet is not a problem on a cellphone but it depends on yourself to maintain and care for it properly. Incidentally I have two cellphones and both use Android, one is specifically for managing wallets and the other for browsing because the internet world is very risky for phishing, so separating wallet security from browsing also needs to be done so that my wallet remains safe.