While I agree that some models improved when it comes to performance (especially in the 1.8 - 2.0 Turbo range as that's the sweet spot when it comes to cc) and technical failures, I would still say that all newer models have more problems with software. So much that it's really not even necessary to create these problems even in regards to regulatory requirements or safety compliance.
Just thinking about the messy code that I've seen to pass ASIL-D requirements makes my skin boil.
I mentioned the ALH TDI from the MKIV Golf/Jetta only, which is a legendary engine, with a ton of them having now reliably reached half a million miles with no major work required. This long predates the dieselgate cars, and adblue was never used on the 4 cylinder VW diesels anyways.
As an aside, yes dieselgate was intentionally criminal, but was sort of the opposite of a quality issue. VW couldn't figure out how to get their engines to work reliability and drive well with current technology at the time and still meet emissions requirements, so they cheated. They had to fix them (I own one) and they are still good, but not as good as they were before the fix- worse fuel economy, less reliable, excessive adblue consumption (in 6cyl models). The ethical thing to do would have been to pull all of the diesels from the market instead, which is what many of their competitors did at the time. Passenger car diesels in the USA are effectively dead because the emissions requirements render them less practical than gasoline cars.
VW had serious quality issues in the 90s that weren't strategic, but were actually causing their company to lose its reputation and nearly collapse. They turned it completely around when Ferdinand Piëch started running things- they were arguably making the highest quality cars at in the world any price point during his tenure as CEO. The quality of current VWs has now fallen back down again, even lower than the 90s cars unfortunately.
My mechanic told me that engine was really poorly suited to city driving, which was a lot of my activity, and short trips caused an inordinate amount of carbon buildup, which he cited as the cause of my cold weather performance issues. Anyway, I think it’s probably a great car for folks with a lengthier commute. I learned my habits and routines were likely murder to a TDI engine, but especially those dieselgate models.
If VW had been trying to make the mk3 engines bad for planned obsolescence, then why did the mk4 engines like the ALH TDI and the 1.8T earn reputations as some of the best engines made? VW had quality issues in the 90s that they later attacked and fixed, but it was just sloppy leadership and engineering, not a plan.
What engine exactly are you seeing broken cams on? My guess would be this is not VWs fault but a mechanic failing to keep track of the ordering and orientation of the cam bearing caps and swapping them around- they’re line bored and any modern engine will break the cam if you do this. I’ve seen it on a mk2 GTI.