The iPhone XS and XS Max both earn a 6 out of 10 on our repairability scale (10 is the easiest to repair):

Critical display and battery repairs remain a priority in the iPhone's design.

A broken display can be replaced without removing the biometric Face ID hardware.

Liberal use of screws is preferable to glue—but you'll have to bring your Apple-specific drivers (Pentalobe and tri-point) in addition to a standard Phillips.

Waterproofing measures complicate some repairs, but make difficult water damage repairs less likely.

Glass on front and back doubles the likelihood of drop damage—and if the back glass breaks, you'll be removing every component and replacing the entire chassis.