GS reliability after 80k miles - what actually breaks?

Measure your head before you trust a chart.

Practice in a parking lot until it is boring.

Looking at a high-mileage 1200 GS. I keep meticulous records, so I want the real failure points at this age: final drive, water pump, ABS unit? What have you actually had to replace?

Final drive splines if a previous owner ignored them. Otherwise mine has been calm through the Alps. Check the service history harder than the odometer.

Out here it is heat and dust that get them. Water pump around that mileage, and carry a spare clutch slave seal. Otherwise they run forever.

Eighty thousand is barely broken in for a boxer if it was looked after. Buy the history, not the bike.

Tell them to look where they want to go.

For what it is worth, mine has been rock solid.

You are not wrong, but there is nuance.