I have to "buy to own" Fallout 76 when the game disc is inserted. I am able to play the...

It's because you own it on disc and not digitally from the Xbox store.

I own a xbox one x, so you mean if I download the digital version of the games the savepoints will be overwritten? So that I have to play the games from the beginning.

No.

If you have the game installed already from the disc, there will be no 'download' to speak of, your disc installed game will become a digital game. For the most part (I'll get top that in a mo), Xbox One games on disc are the same as their digital counterparts.
Your save games are not effected and will work just as before.

When I said 'for the most part' I'm referring to games that have been changed so much that the disc isn't used to install the game anymore, it's only used for proof of owner ship. For example Halo MCC was bigger than what was available to store on Blu-ray
disc, so part of the game was a download. Now, Halo MCC has changed so much that the disc doesn't install anything, the entire game is a download.

The same is true for Fallout 76. When it first came out most of the game data could be installed from disc along with a game patch. Buy Fallout 76 now and insert the disc and you'll be prompted for a 50GB+ Xbox Live download, practically nothing on the disc
will be installed.

These two examples don't change anything about the licenses, buying a game on disc on Xbox One is just a install medium, nothing more.

I cancled my gamepass subscription, now i cannot play the games i own, any game that was on gamepass (IE: Minecraft, skyrim, halo MCC, fallout 76) will no longer work on my xbox EVEN if i have the physical disc inside the xbox, i have 100% confirmed the disc work and i have confirmed my disc drive 100% works, everytime i click on it, it tells me i dont own the game and i to need to buy it... i just want to play the video games i paid for

ALREADY HAVE THE DISC FOR meaning I have to pay monthly to play i game I already bought if this is an issue I would like to know thx now imma go buy it again on steam thx Xbox

Unlike the previous Fallout 4 game, Fallout 76 is an online only game. Therefore, regardless of whether you own the game on disc or digitally, you will still need an Xbox Live subscription to play. The can either be an Xbox Gold sub or Xbox Game Pass Ultimate.

Just so that I am understanding correctly.

You have 2 friends that own a game one has a disc and the other is Game Sharing with the one that has the disc?

If this is the case.

1. Neither one of them own the game digitally so in order for either of them to be able to play the game they would have to have the game disc in the console and keep it in the console in order to play the game.

2. It sounds like you own the game digitally that is why you are able to play it unless you have the disc inserted into the console.