DSG faults are not unique to the GTI - Take the Evo X for example, which has a comical design flaw that prevents you from selecting any gears. Box has to be stripped down to glue a sensor positioning magnet back on! Doesn't happen on VWs.
Chain wear - It's a chain. They wear out. Again, not unique to VW. They don't last forever on bikes either.
Rust is not unique to the GTI - It's steel and wants to return to it's natural iron oxide state. No escaping that. No steel body shell lasts forever. It affects all cars, even Japanese ones. If you live by the sea in a cold climate, you're on borrowed time. If you live in Florida, not so much of a problem.
Failed PCV / DVs - Again, other cars use the same design and plastic and rubber is certainly not going to last forever. GFB DV+ is a simple solution for that.
Cam follower - A bit of an internet folklore problem and not an issue on standard cars with a good oil changed in a timely fashion.
Wheel bearings - Ditto the chain. It's a wear item and not a design flaw.
Thermostat failure - Again, not a unique problem to the GTI. At least with this car it seizes open. Try an E39 BMW with it's electrically controlled thermostat that jams shut, plus the part is 5x the cost of the GTI part.
Charcoal canister - Really? A plastic box has been listed as a flaw/problem??
Saying that other marques have worse DSG issues is not very reassuring lol.
The chain *should* be a life time of the engine item, if not it should be in the service schedule, and isn't it normally the tensioner which fails, meaning the chain can slap around, rather then the chain itself stretching?
Rust - i'm sorry but VW messed up on this, I know all cars rust, but very few modern cars seem to be going as badly as the mk5. What are the known areas - wings, cills, rear arches, boot, that's basically every panel lol? I see 20 year old Peugeot 306s with less rust than that, if a cheap French hatchback can last that long then IMO it's a poor show that a premium brand (with the price tag to match) cannot do it.
DV/PCV failures - yes fair enough not a difficult or expensive fix, but still another maintenance item.
Cam follower I think is a poor design - should at least be on a visual inspection as part of the service.
Rear wheel bearings are wear and tear, but the GTI does seem to go through them more than other cars, whether that's due to the geometry/axle design?
Thermostats are a common point of failure across many cars, but again it just seems like between the main and inline ones, many owners have had to replace them.
I thought there was an issue with the charcoal canister where a valve failed and then if you brimmed the tank it ruined the canister and had to be replaced - could just be inaccurate info I read online though?
I understand quite a few of the issues would technically come under wear and tear, but then there aren't many parts on a car you could argue are not wear and tear. This is probably just me, but I consider standard wear and tear parts to be brakes/tyres/suspension/bushes/clutches/cambelts, things like that, once you start getting much beyond that you start to wonder if it could have been engineered better.
I suppose at the end of the day much of the complexity required in modern engines comes from the demands of emissions/power/economy.
Interesting thread so far!