The clutch failed on my 2016 (just out of warranty) 2.0 GT Golf (27,000 miles). I took it to my local main dealership where I have it serviced. I know clutches aren't covered after 6000 mile/6months as they are generally classed as wear and tear items.

£75 for diagnostics (no fault found).
£105 for hydraulic inspection (no leaks found)
Advised to replaced Master Cylinder (£508) and do a brake/clutch fluid bleed and refill (£96).

Problem seemingly solved and I drove the car away feeling miffed at how much it had cost.
The next morning the clutch sprung down to the floor under tension as soon as I depressed it. 10 hour wait for RAC due to flood emergency recoveries (and as I was in a safe location at home). Work furious I couldn't go in.
Towed back to VW to be told it was the Slave Cylinder (£900 repair).

Refusing to pay any more I contacted customer care. They agreed to pay the remaining costs.

Is it common for the slave to go after 4 year years of careful sparing use? I've never had a clutch fail on me.