I bought my Mk7 in 2017 (when 3 years old), and have enjoyed 9 years of motoring except:
Used coolant, VW replaced coolant bottle and I think water pump under warranty after 6 months of ownership, been fine last 8.5 years.
My Drivers mirror glass also fell off on motorway
Alternator went at 60,000
First set of new discs and pads at 50,000
1 x new Battery
Heater matrix blocked, very common on many VW/Audi/Seat, new one installed, car now burning hot!
Drivers door electric window switch broke, replaced myself with OEM
No gearbox problems as auto
Normal Alloy white worm, wheels refurbed
Infotainment was crap, paid to have later VW OEM CarPlay headunit installed, its great
I think that is everything, all in all, I am very impressed with it, and will be keeping it for as long as I can, as it is now being talked about as peak car, ie. no lane assist or other boll0cks no one wants!
Sounds like you have been unlucky, but obviously all second car cars have issues. I wouldn’t touch a 8, better off with a 7.5 IMHO