Wasn’t it mastered on D1? At least that’s what I read somewhere, that TNG was mastered on D-1 and later they upgraded to D-2,
Probably, but some local U.S. tv stations outside major cities were still using analog broadcast formats. Satellite delivery of tv shows was more economical and practical than sending tapes out. (And digital tv signals didn’t exist yet.) Unless you lived in a major tv market, you might not have been seeing shows on the same format they were mastered in. And if you didn’t have cable tv, that’s a different can of worms.
Laserdisc releases of TNG episodes probably looked better than most broadcasts did.