Don't think anyone with sense claims any of these are
universally superior. Each had merits and de-merits.
Think it goes something like this:-

NTSC gives the best pictures in the studio.
SECAM records best.
PAL transmits best.

#1 is meaningless, because "in the studio", you can display RGB directly,
without encoding.

I remember an article about 15 years ago in one of the pro publications
arguing over color TV standards. The author -- who was someone famous (it
might have been Henry Kloss, but don't hold me to that) -- said that the
best color TV images he'd ever seen were NTSC. He was talking in terms of
optimum reception and display.