Consumers may complain that this behavior results in higher prices than they would otherwise pay. But I suspect those prices are likely only raised at the margin, to some degree that shifts consumer surplus from consumers to sellers. They aren't being priced out of the gasoline market entirely -- were they so, total sales would fall off signalling reduced demand, and we'd expect prices to fall accordingly. Copying here is sellers following those prices that best capture that surplus. I'd be more worried about collective behavior that restrained market entry by other sellers.
Also: this discussion is focused on the short- to mid-term. The overall price level, even if shifted among possible equilibria by collective behaviors, signals demand to producers. A high gasoline price raises oil prices which increase incentives to find and produce more oil. As that oil comes to market, supply increases and price falls.
tl;dr Free markets promise "best", not "perfect", allocation. Not clear that these tacit cooperations do more than move prices within possible local equilibria so as to capture more consumer surplus for producers. In any case, prices still serve, over the long term, to signal returns to investment in production.