I think of blind/random minis as a very new thing (because I'm rather an old thing, myself, I guess).
And, clearly, a thing inspired by the CCGs that gave WotC life.
That said, minis were a huge part of wargaming back in the day,
and of D&D, which grew out of wargames. And they were toxic lead.
And we were glad to have 'em.
And, yeah, they were a comparatively expensive part if you bought a lot of 'em.
And, y'know, we used dice and pawns from other games and whatnot when we didn't have a mini, so