For one most engines are pretty much at their peak efficiency, for two practical safety features reached peak between the mid 90s to the early 00s. Most modern safety features are ironically enough not all that safe, for example lane assist makes people pay less attention or it tries to assist in the lane and overcorrects. I see the latter rather frequently in my area since windy roads, usually the damned things are trying to avoid the white lines of the shoulder and overcorrect over the yellow.