Correct me if I'm wrong — if we use an open source Bitcoin wallet but after getting the address and seed phrase stored in a waterproof and fireproof place or not damaged by water and fire, the wallet is uninstalled from the mobile device, I think that's one way to use it well. Is it right?
Sounds like you're trying to generate an air-gapped wallet/cold wallet but using a mobile phone to generate the seed, is that right? I'd rather use another device, like a freshly installed/disconnected computer or a live OS to do that instead of a mobile phone. Unless you disconnect your phone, reflash the OS/ROM, and then destroy it I don't think I can feel safe. Might as well buy an open source HW. CMIIW.
What I mean is, for example, there are people who want to use a mobile wallet that supports android or ios that is included in the recommended wallets such as electrum and bluewallet, but the person only installs it on the device to get the address. After getting the address and seed phrase, it is stored in a safe place, then the application is uninstalled. Is that the right way?
Personally, I am the same as you in that I am safer using a hardware wallet.