My son is currently obsessed with LEGO. He probably got six different boxes from his birthday, and in the past month, he built all of them. We ended up ditching video games in the evening in order to build LEGO, which I was really excited about. Obviously, he was too. By the last LEGO kit, he only needed a little bit of guidance and was building the kits by himself.
I recently finished a STEM course in my education classes where we talked about the importance of spatial reasoning. The LEGO kits do a great job at getting kids to look at what blocks are required, how many, and where the blocks need to go. It also works on their fine motor skills. I really love watching Jack as he follows directions to create something from only blocks. The smile on his face when he completes a kit is priceless.
Additionally, it has been really interesting to see his imagination soar as he plays with the products of his different kits. He also has a box of loose lego that he has been using to add to his kits to create even more imaginative things.
While the prospect of LEGO blocks everywhere is definitely a point against LEGO, I really think that it is an important tool for learning for children. Between the building, spatial reasoning, fine motor skills, and creativity that is used, it is a very well rounded toy. When Jack is older, I think we will probably invest in a LEGO robot so that he can learn the basics of programming as well. Until then, we will keep playing with our current LEGO and help him build up his creativity and building skills.