The lower in elo you go, the less counters matter and more the skill difference does.
As you go higher in elo, people are increasingly able to play their champs to their full potential, and only then do counters start mattering much, and by that point it's more of a 5v5 game, so even being countered in lane isn't that big a deal if your champ still fills an important role in the overall comp.
Bronze is awful, so players there are barely scratching the surface of most champs potential. If someone is capable of playing like 50% of champion X's potential, and their 'counter' is only being played to 30% of their potential, then they'll probably stomp their 'counter' despite it being a 'counter'. In both cases the players are still awful, so their raw skill is still quite low in absolute terms, but it's the difference that matters.