What phone is better?

Compare the specs of those two devices using this link:--> iPhone - Compare Models - Apple

and choose the one that better meets your needs.

Regards

Giulio

Technically speaking, it would be the Xs (Max).

But in the end, the decision is up to you. You'll need to decide that.

See this for a comparision. You can select Xs Max and Xr from the drop down menu.

https://www.apple.com/iphone/compare/