Wallet security lies in how users use it. If you still rely on mobile wallets and active internet data access almost all the time, then security will not be safe.

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?