They were sued in the EU for violating anti trust laws, lost and decided not to cooperate.
They’re currently getting sued for forcing devs to not sell their games at a lower price on other platforms.
Their marketshare is more than enough to consider them a monopoly, you don’t need 100% of the market to be one, you just need to be so implanted that you become the default solution. Google doesn’t have 100% of the market, it still is considered a monopoly for search engines