> The 66-year-old brick will have the exact same interference fit, the same clutch power, the same 4.8mm stud diameter.

Pretty sure this is false. Old bricks had way higher clutch power, so high that it was deemed too difficult to separate. Sometime in the 90's the grip strength was reduced.

This false claim is underpins the entire article :(

I concur. I had "inherited" the sets of my 10 years older brother, and they where a pain to play with. It was sometimes impossible to separate the pieces, especially if it were plates with no leverage and nothing to grip.