It leads to lawsuits not to break monopoly, but to extract money. In some countries money is evil over a certain amount.
It doesn't matter where you are, hoarding while others do not have enough is evil, and hoarding cash (the wealthy currently have unprecedented cash reserves) exacerbates that. We need currency to circulate in order for the economy to function, so we print more money, and therefore the currency hoarders literally cause inflation. We keep hearing about the "job creators" but currency hoarders are job preventers.
With that said, none of that is relevant to whether the EU has the right to use lawsuits to break antitrust which is not monopoly-related. Insisting that only monopolies are relevant to laws which prevent anticompetitive actions in marketplaces is ignorant at best and therefore your focus on monopolies is likewise. But I don't believe you're that ignorant, which makes it seem more like malice.