Everytime you post i am amazed that you can get even dumber. By your own definition, it is a backup, if he lost or distroyed his original disc he would still be able to play his "backup" data that is installed on the HDD.
if he "backed up" his phone would it not be a backup because he didn't clone it to another phone?
when people convert physical carts to xci or install it as an Nsp's to their switch is it not a backup because its not on a cartridge?
The installed game is not a backup by my definition, "a copy of a file or other item of data made in case the original is lost or damaged.". I guess you like building strawmen. The installed game is to speed up data access, not in case the original is lost or damaged. If the original is lost or damaged and you need to reinstall the game, then you don't have a backup.
If you backup your phone and can't restore it to another phone, then it's a pretty shitty backup.
Making a copy of a cartridge onto your sd card so that you can install the game on a different switch, is a backup.
Please, keep demonstrating your cluelessness.
would be a "copy of the original disc" aka a "backup"?
The installed copy is not equivalent to the original disc as you can't use it to install on another PS5.
If you can ftp the files off your PS5 and put them onto a new PS5 and run them with this method, then that would be a backup in case the original disc was damaged.