Have none starting with 1 been assigned, or is there some technical reason there are none?
"The syntax rules for area codes do not permit the digits 0 and 1 in the leading position."
My guess would be it's to avoid ambiguity with the fact that 1 is also the country code. If I recall correctly, historically, dialing the 1 was necessary for any long distance call (even if not international).
You recall correctly. I haven't had a landline for a number of years now but I think it was still required latterly when I still had one. Don't think it was ever needed on cell (or maybe even valid) when I first got one at some point in the 1990s.