WHY so few "other brands' left out there?( Admiral, Sylvania , Philco, etc)

[ChrisW6ATV]

I am an odd combination here: A TV technician (for over 30 years so far) who has repaired hundreds of Sony sets (monitors, actually), and who would still to this day never buy anything BUT a Sony for a new CRT display (if we even still could do so!).

Trinitron CRTs just plain beat everything else by a mile, in all of the years I ever compared color CRT displays, from 1979 when I bought my first, through the 2000s when I liked the widescreen HD Sony sets but had moved on to rear-projection sets (which were also Sony CRT sets).

Back to the original subject of this topic, more or less: When Sylvania was advertising their "Supersets" and claiming they beat all others-including Sony-in comparisons, I never did go and see how those sets really did look. Are there very many "Supersets" still around, compared to the number of Sony sets still in existence? Do any of you have opinions on their quality at the time?