It’s nothing to do with material quality. I’ve had a VW Up GTI for 4 years which is full of hard plastic and bare metal and it hasn’t rattled once in 30k miles. My car is unusual for VW in my opinion, Golfs have always rattled
My 2020 Polo GTI+ that I’ve owned for 31 months since new also has hard plastic interior trim (door cards) which seems to be the norm these days for B segment cars. Apart from an intermittent vibration from the storage cubby in the lower centre console a couple of years ago (only happened a handful of cases on a particular stretch of road and then stopped, never to return), there’s been no unwanted interior noises in my car either.
IMHO hard plastic interior trim isn’t necessarily poor quality, although that’s the general perception. Granted, it’s not as tactile as soft(er) trim, but then I don’t sit in my car and fondle those pieces of trim like the dashboard which is soft touch
, and I’m not looking at the door cards when I’m driving. Although soft interior trim does look nice, if it’s going to be a source of constant unwanted creaks and rattles, I’m happy with what I’ve got (unwanted interior noises are a pet hate of mine).
For me, quality is just as much about how well something is screwed together as it is about the materials used. I suspect with the Golf, VW may have cheapened out in areas that aren’t seen in an effort to control costs, and they may have used fewer, poorer quality clips and fastenings to hold the interior trim in place. There’s also a massive backlog of orders at the Wolfsburg plant, so maybe some areas of quality are being compromised on the Golf’s production line and the post-build QC process in an effort to clear that backlog.