If there is such a thing as gold heaven, it's low gold. That's the best batch of non-toxic players you'll ever find.
I can vouche for what you said, I'm in gold 2 right now, almost 1, and you can't imagine the toxicity of the players. The problem is, almost everyone expects to have things go their way, forgetting that they're in soloq and not in team ranked.
They always have plans in mind, rules they play by, that no one else knows, and if something goes differently than what they had in mind, you can expect the whole game to turn into. countless amounts of shit talking, regardless if you're extremely ahead, or not at all.