But how can it? If a player is apparently much better than it thinks they are?
This is why you cannot queue with people more than 1K SR on either side of you (or 500SR if you’re Diamond+). So stuff like this cannot happen.
If you lose to high gold players as a silver, you will only be lightly penalised. If you win, you’ll be highly rewarded with SR (as long as you performed well in the game). But if you’re actually a plat player with a silver rank, you will beat gold players (because, you’re better than them) and be highly rewarded with lots of SR because the game thinks you’re only silver. Thus, you will climb quickly.