What "fix" did Riot implement into Flex Queue?

I just played a game where we had players ranging from Bronze 2 to Plat 5 soloq rank. And while it might not be quite so bad as what some streamers have been complaining about (Bronze and Challenger players in the same game!), it's still pretty ridiculous.

Never mind the fact that your so called "rank" in flex queue seems to be an entire tier below the opponents you face. Eg. Silver players have a bronze rank, but still play vs other silvers, golds ranked silver face gold players, etc. Good luck trying to climb out of that mess!

Is it so very difficult to have some sort of restriction, so that players three divisions apart don't have to face each other?