The Google Pixel 3 XL earns a 4 out of 10 on our repairability scale (10 is the easiest to repair):

The only screws are standard T3 Torx fasteners.

Repair-friendly stretch-release adhesive secures the battery.

O-rings and adhesives for waterproofing complicate repairs, but make difficult liquid damage repairs less likely.

Display repairs are much more difficult than previous models, requiring complete disassembly of the phone.

To service any component, you'll have to painstakingly un-glue (and later re-glue) the glass rear panel.

Front and back glass means increased vulnerability to drop damage.