So... the article... Hypothesizing that it's primarily due to tight tolerances. Shows that they're indeed tight, and have remained similar to legos made 40 years ago. However, similar to what appear to be "random cheap dollar store building blocks." Best sentence "Honestly, I don’t know much about plastic manufacturing – but the LEGO blocks appear to be created from harder plastic." - This is why they made interviews. Really wasn't so interesting and didn't answer the question.