What if I delete a crypto wallet that still has a bit of crypto in it? For example, will the Bitcoins left in a wallet I would delete disappear forever, never to return into cirulation? (I actually did this a few times already, except that they were accounts of crypto faucets....)
You can uninstall your wallet, delete the wallet file in your device but your coins will be on the network, in total supply. If you wipe out your private key, you will lose your coins and no one can get them. If they can not have access to your wallet file, brute force it, and so on.
Coins, when are launched, mined or minted, will exist on the network forever, if no burn actions are done.
Delete, uninstall a wallet is different than burning coins in an address.