Agreed, the Sesame Street “old school” episodes made from about 1969 to about the mid to late 1970s were probably that much more better than what passes off for educational TV today. Maybe this is my own personal bias talking but this can also include “The Electric Company” and “Captain Kangaroo” even, from about that same time.
I agree with you that those old episodes of Sesame St. were the best ones. The switch from Grover to Elmo as the lead host was a bad move and a dumbing down of the show. I was born in 1971, so it was those old episodes that I watched as a child. Perhaps today’s children would be better off if they stopped making new episodes and only aired the ones from before Elmo became lead host.