I'm not even close to challenger but I know what is happening because it happens in my games too. Before the meta settled in I had a lot of success hyper-rolling early for 3 stars and forcing rangers-guardians and draven comps because most people were going void/sorcs or rengar carry while leaving the items and heroes I wanted open. That simply stopped working for me now that those comps are contested as well. Instead my power has to come from getting high cost units with the right items, not early 3 stars.
Wolves come right at the biggest powerspike in the game for just about every meta comp right now. 4 imperials, 4 rangers, and 6 sorc comps come online. People are rolling for 2 star chogaths, dravens, & sejuani's and A-sol's before they're all gone. Units are getting sold to transfer items to more powerful carries.
If you have 80 health by then you can afford hp wise losing more rounds in order to eco and grab better items in the early game, then all in at wolves when your gold is best spent.
Pretty much to winstreak and roll to victory you need either, godly luck, econ from pirates, or to 3 star a bunch of uncontested units. (Most units that have been nerfed in the past were only nerfed at 2 stars & below... demons, assasins, volibear still have surprisingly strong carry potential if you 3 star them).