sony is not yet a gatekeeper, might be in the future... apple does not have to sell in Europe, if it does, and big enough (no need to be monopoly) to be a gatekeeper, law and rules say they operate a critical infrastructure/platform in the EU economy and hence they cannot tax developers (a country has such powers)
the question is not whether Apple has to change but a question might be why? this is the field of monopolistic power and competition law... monopoly profit is not inherently bad, can help innovation but along the way we figured out it is probably best to curb this power in the long run
Apple had its time of their life and to be honest, I see little meaningful innovation in the last 5+ years, however, they suppress competition and innovation in the economy, controlling a gateway between innovative developers and users
another aspect is consumer prices... should consumers get lower prices or let apple take monopolistic tax from them? of course lower prices seems to be better nd it is one goal... however, we should and we do allow success and monopolistic profit by each and every big innovation, in the beginning and Apple has already had that
it is a bit like an economy supports patent law and competition law at the same time
most people are motivated by financial success and most company pay research and innovation for potential monopolistic profit and this works and it is protected! however, competition law or new forms of it like DMA kicks in later on
it is like you innovate, use patents, get big money but if you grow big you are not allowed to become like all companies become if not controlled: shifting from competitive innovative power to a country like taxing power
I think it is correct that we need competition law too, if we really think about our past, economics, history, and what motivates people