Amiga 1000 was released in mid-1985, although I think few units were shipped before 1986. Amiga 500 was 1987 - same year as VGA, its little brother MCGA, and the Mac II.

Not sure when VGA would have been considered mainstream... 1989 maybe? Mac LC was 1990, so probably before that.

VGA and Mac color were better for most practical things. Square pixels and far fewer resolution/flicker/color tradeoffs.

Amigas reached hobbyists in large numbers way earlier, yeah.