The first-gen 4.0 AJ-V8 did have those chain issues you mention, as well as Nikasil bore-wear. Now, the high-sulphur fuel that caused that problem is long gone, but the Gen1.5 AJ-V8, as well as the Gen2 and Gen3 versions (4.2 and 5.0 respectively), have all had cast iron liners as well as better tensioners & guides... BMW and Porsche (who also had Nikasil issues) moved to Alusil liners which, touch wood, are fine...
I wonder how many of the old battleship Whirlpool/Kenmore dryers are still purring away after 40-odd years? Or the Maytag 808 etc "Stream of Heat" machines? Simple designs, but robust and reliable, if not as nice as a Filtrator... I'm guessing they cost a fair few bucks when new, but when you amortise that across decades of reliable service and account for the consequent peace of mind...
Alas, it does seem that the accountants have taken over. We all saw what happened when they took over Mercedes-Benz in the 90s... the legendarily robust W124 E-class was replaced by the infamously fragile and rust-prone W210, which was designed and built entirely by engineers to prove exactly what they were capable of (along with the fabulous W140 S-class and R129 SL). They STILL haven't lived down the resultant scandal and whiff of unreliability in terms of public perception!