You don't delete wallet but can delete the wallet app, meanwhile everything is intact in that wallet. All you need to do is to import your seed phrase to be able to access your wallet once again. You can only be more confused if you deleted the wallet app without keeping your seed phrase safe. non custodial wallet e.g trust wallet, metamask and electrum wallet can only be recovered by keeping the seed phrase in a safe place to be able to used them to import your wallet again.
Before deleting/ uninstalling a wallet on a device, you must be very sure that you already make wallet backups, not only one but several back ups. It is not enough if you stop there, because you have to test that you can recover your wallet with backups you have. Make sure through testing, your recovery result shows that you succeed to recover a same wallet on your device.
If backups done, wallet recovery test result is good, you can delete that wallet in your device.
Lastly make sure you store your multiple wallet backups safely so that you can have good ones for wallet recovery later.
Deleting your wallet or not, if you lose your private key or mnemonic seed, and don't have backups, you will lose your bitcoin.
Not Your Keys, Not Your Coins.Bitcoin Q&A: Not your Keys, Not your Coins.