naa
its customer dictation!.
Its actually what the customer demands, no customer buys a new car now to drive for 25 years, The first owner at maximum will drive for 3 years, second for another 3 and then its scrapped 80% of the times regardless of brand and origin.
All new customers want an amazing finish interior, all features of an 2000s Merc S class, swoopy lines, starship acceleration, striking looks and 100 mpg with a bargain basement price tag. - They dont give a shit about how its manufactured or assembled, 99% of them dont even know or want to pop open the bonnet/hood for anything including windshield washer topup (because thats the dirty mechanics job).
The plasticky parts are done for weight reduction and cheaper manufacture - look at your old 2004 onwards corolla, it uses a plastic intake manifold, plastic thermostat flange etc etc, - the reason its done is to reduce production cost and to make a smoother finish (win win for both customer and manufacturer, as customer doesnt care for a manifold (they dont even know what it is) and manufacturer can spend that saving on some fine stitching or something like optitron meter etc. (plastic manifold breaks/warps/cracks)
while older corolla with the A series engines had a cast aluminium intake manifold that had braces to prevent vibration fracture - its service life is almost infinite. but the 100 series corolla doesnt have anything like optitron or a spacious interior etc.