Do all xbox 360 games work on the xbox series x?

Because of backward compatibility.

Yes, I believe almost all of them, and if there are exceptions, it was somehow 3. Microsoft attaches great importance to this.

No. You can only play specially selected ones. On the Microsoft website there's a list of all games that will also run on the Xbox Series X.

@blessthiskid is wrong. ALL games work. If the game is not available digitally in the Microsoft Store, the disc version will still work. You can get them cheaply on Ebay.

Xbox Kinect is the only system that doesn't work. Even the game Skylanders works, for which you have to connect extra hardware.