Why games is downloaded on all Xbox accounts

That would be tied to the Home setting. On your Home console, any other profiles on the console will have access to any games you install. If you don't want to share them with the other accounts, you would need to remove the console as your Home. You will still be able to play the games as long as you are signed in. https://support.xbox.com/en-US/help/hardware-network/console/my-home-xbox

Does your account region match your actual region if not that would be why

Most triple a games are region locked that's why if you can download some doesn't mean you will be able to download all

For the best experience with Xbox live. You must live in a Xbox live region and your account region must match that

Why not use the other account? If they are on the same xbox, then all accounts have access to anything you download, except avatar items, those are tag specific. Also, if the other account isn't gold, it can still download stuff.

because all xbox downloads are tied to a single account? nothing else transfers over. not sure why you expected this to.

I'm unsure as to why they aren't. Have you tried searching through the game pass menu? Does it still not let you download them?

The game pass menu doesn't appear at all, when my dad's account isn't online on my xbox, the Gamepass tab isn't there at all, but when it's online on my xbox, it suddenly appears back so even if i downloaded the game, it would disapear soon after i logged off
the account