For example, one of the keyboard apps that I use works as a QR code/bar code scanner (very useful for quickly transferring credentials from a desktop/laptop computer without exposing credentials to Android's clipboard, were some apps are known to try to sniff and exfiltrate clipboard contents whenenver they get the opportunity).

And of course, there's a FOSS app to alleviate the problem at least somewhat:

https://f-droid.org/en/packages/com.kunzisoft.keyboard.switcher/