Is there any reason to think they're any less reliable than a standard gearbox? Or any more complex to repair? I don't know how easy it is to replace the clutch(es), but I would have thought they're less subject to wear than manual ones (only half the use per clutch, less subject to abuse such as riding the clutch, etc).
More complex labour wise to repair them/replace clutches.
Likely many independents won't touch them, hence dealer costs.
Parts availability for any repairs at this time will be Genuine parts only I believe. (Although I may be wrong)
The clutch gets most wear pulling away, so the first gear clutch is still going to get worn at a similar rate to a normal manual car.
Time will tell I guess.....