Why was the multi image technique abandoned?

What initially "killed" this technique was the fact that, until relatively recently, all movies used to be broadcast on TV in godawful "Pan & Scan" mode -- which utterly destroyed the multi-image experience.

Bad enough for a director's vision to be ruined because the aspect ratio was screwed up (2.35:1 to 4:3!)... With multi-image cinematic "panels", the destruction was even worse.