Hopefully this will give people pause the next time they think about linking to https://xkcd.com/1357/ .
XKCD's point stands as long as nobody has a monopoly on an important medium. Apple and Google effectively do have a duopoly on mobile app distribution, and mobile apps are an important medium for speech in 2025.
IMO, we need to stop thinking in this broken paradigm of "-opolies" (with its loaded requirement to define what constitutes a given "market") and look at the actual coercive power they wield through market stickiness. Apple and Google both wield much coercive power with regards to software running on mobile devices.