It's perhaps worth remembering a couple of things about modern engines and oils:
1. For decades past, in the UK the majority of new cars have been sold as 'company cars' whose drivers are unlikely to check anything unless a warning light comes on. Long service intervals are a key selling point. Once a car is out of warranty, the quicker it dies of neglect, the better for the manufacturer! Alfa suffered a spate of premature engine failures on T-Sparks because the idea of topping-up the oil between services is completely alien to a lot of company-car drivers - when the oil pressure warning light came on, it was too late.
2. Short and stop-start journeys are hardest on cars in general and on engine oil in particular because the oil rarely gets hot enough to evaporate the condensation that builds up from the engine not getting fully hot before it's stopped and allowed to cool.
On the subject of tool kits on old cars; back in the early 1970s, I had a Porsche 356 (built in 55 IIRC). The engine could be removed, stripped and rebuilt using only the toolkit: 10mm & 17mm spanners, 10mm and 17mm tube spanners, 10mm allen key (long), plug spanner, screw driver, pliers. The works rally mechanics reckoned two of them could change a clutch in under 20 minutes! Compare this to the array of standard and unusual sockets, spanners and special tools required to do major jobs on a Xantia.
Guy