Computer aided design & manufacturing automation along with computerized engine controls and oil and fuel technology are primary reasons why the engines of today are so much better than years past. This is reflected in thinner oil for tight tolerance lubrication and fuel economy. Not just the viscosity of the engine oil has thinned, but also the "generic" duration between oil changes has increased from 3000 to 5000. Vehicle, oil, and fuel technology has changed a lot and so I follow what is recommended in the owners manual. As of late, I change the oil in all my vehicles at 5000 mile intervals (3000 miles in the past) using full synthetic oil because I get it on sale for less than $3 a quart on a regular basis. Otherwise I would use regular oil. I think our 2014 Nissan Altima manual states to change it less frequently,maybe 7500 miles, maybe later yet, I forget. But the old school in me says to change the oil more frequently at 5k.
One other common misunderstanding is the use of higher octane gas than specified in the owners manual, and it's consequences. But that is another topic.