Wallets do not hold or stirey the funds in your address, rather they help you access it. In simple terms, your Bitcoins (or at other cryptocurrency) are representations on the blockchain with public keys which you can use to check the balance and transaction history or to sign new transactions.
If you use electrum wallet for example and have an address on it with some Bitcoins, deleting the wallet software doesn't delete the coins as well. With a backup of the phrase you can always recover it. If course if there is no backup seed phrase and the wallet file is deleted, there's no other way to spend the coins in it.