Game Pass Ultimate Family Subscription

But my subscription is for Game Pass Ultimate and not for Game Pass for PC... My family should have access to the games, right? Otherwise, what is the family plan for?

Game Pass Ultimate Family ended in August. So you wouldn't have a subscription through that currently.

It sounds like you're sharing his subscription through the Home setting on the console and not an actual family plan. If that is the case, you will only have access to this subscription on the console.

If you live in one of the regions where the Game Pass Ultimate Friends and Family Plan is currently available (Colombia, Chile, Hungary, Ireland, Israel, New Zealand, South Africa, and Sweden) your dad would specifically need to purchase that plan and not just regular Game Pass Ultimate and then add you to the plan as well. https://support.xbox.com/en-US/help/subscriptions-billing/manage-subscriptions/xbox-game-pass-friends-family-faq

With the Family and Friends pass, everyone you add to the plan will have access to the Ultimate subscription. You would still need to use the Home setting to share any other games that are not included with Game Pass.

Worth is subjective. If you have a family that has multiple consoles, then it's typically worth it to buy the 1 subscription.

If that family member's Microsoft account does not have an Xbox Live Gold (or Game Pass Ultimate) subscription connected to it, it will then have to rely on whatever subscriptions that their device's Home Xbox setting has with it. The Microsoft account
family feature does not extend subscriptions to those accounts.