[bluetomcat]

Even the vehicles in 5+ City sets are affected by this trend. It takes about 50 parts stacked in intricate ways just to build the base chassis structure of a van, for example.

In the 1990s, Town vehicles were 4-stud wide and didn't focus on the small detailing. The instructions for the original vehicle were just a single sheet of paper with less than 20 steps. You could build the original vehicle by memory after having built it a couple of times with instructions. The back of the box suggested alternative builds, which, although looking "imperfect" were a solid base for imagination.

[rkangel]

There is a good range of "3-in-1" sets that are good at starting kids off building the same bricks into multiple models: https://www.lego.com/en-gb/themes/creator-3-in-1

Once they've got a few sets like that, the rebuilding into unspecified stuff seems to come naturally (at least with the cousins and friends kids I've played with).

[Freak_NL]

Those complex sets are great for stimulating certain types of spatial reasoning, perseverance, and fine motor skills. My four year old went from 'building a tractor (60287) with dad helping' to 'building 5+ kits all by himself'.

The kits don't stop him from just building his own stuff either. The two forms of play seem complimentary.