I can only give you an anecdotal counter point but Lego is still fine. Instead of asking for a universal building set like I did, my 5 year old old son now ask

I can only give you an anecdotal counter point but Lego is still fine. Instead of asking for a universal building set like I did, my 5 year old old son now ask for a specific Chima or Star Wars box and then we build the vehicle on the box. After that things get still get ripped apart and combined into new things. It's still mostly a bunch of colored brick except the modern boxes contain a couple more custom bricks which make his own creations look even more awesome. Lego is still a good (or even better) for kids nowadays than it was 30 years ago.