I would not really say they started it then,
im thinking back to the 90,s with the
UD electric courts, and electric court golds,
then the players club and platinum variations.
so the concept of variations of all base cards has been around a while...
Yes that is true, but that was a basic parallel or a main set. But the main set had lot of other inserts etc.
There were usually only maybe 1-3 parallels of the same base card.
But then Finest came out in the early 2000 with the different colour variations, up to about 8-10 parallels? Then soon after almost every single insert set needed to have their own parallel.
With Topps instead of a gold and platinum, they ended up with base (white), red, green, black, blue, (any more?) then refractors of each of those and x-fractors of each of those, and then superfractors of each of those. All the same card.
Yes, parallels have been there since the early 90's, but parallels really became too much in the 2000's.
They thought, well if they want one card, then they will want all 3 cards of the same player. There are the richer collectors who want only the ones numbered to 10, since the 5 year old will be getting the normal un-numbered base. You'll have those who want to collect the 'master set' and the 'rainbows'.
Ultimately when they are all only varied by a colour change or foil change, but the same card then it becomes a marketing ploy. It is a bit different lets say when you have those /100 was no jersey, /50 with jersey /10 with patch, /5 with auto and patch.
But this is getting off topic!
I do like my 1/1, but when there are so many out there, it can become a process of futility for a player collector.