My personal gripe is that they did away with the studded beams in Technic and everything is smooth beams now with axles and pins.

While it might look marginally better, everything is 3x the parts and the building time, and you can just sit down and slap stuff together any more, in fact with the rise of things like Arduino, and 3D printing, I think it's easier to just do electronics + CAD (even with kids) than to work with this stuff.

Which is a shame, because older sets used to be cheaper and contain much less parts for the same amount of functionality, and something like a crane truck set that could do all the tilting and motor stuff was categorized as suitable for kids 2-3 years younger.