Which first shooter online games on Xbox Free or Xbox Game Pass is famous and good to play?

I like Apex Legends, but it's very difficult and Battle Royal… I'm looking for games where there are only 2 teams against each other

There are generally no shooters to play well on consoles.

Apex is difficult only at the beginning. The learning curve comes with every match!
There are of course enough other shooters. Almost all of the major titles run on the Xbox.

How about Battlefield 1? But these are more teams. And that's in the Game Pass