Ranked matchmaking question

So I know riot recently added a gate for what level players you can duo with (for example bronze can duo with silvers, and silvers can duo with bronze and gold) to prevent people getting carried.

After the not-so-soft reset, there are a lot of gold/plats/diamonds getting reseted into a tier below and I just perceive it as a challenge when I have to face against them (Silver 1 against a Season 4 Diamond).

But today when i was playing my promotional to Gold V, there is a Plat V on the enemy team. Why does this always happen? If I want to get to Gold, shouldn't I prove it by beating Gold players?