My advice is to immediately rebrand as gracefully and effectively as possible and use all that activist energy to effect the transition.
They kind of have a point which doesn’t make them right, but they hold all the cards and you will lose this one and regret the wasted bandwidth.
This is why it keeps getting worse and worse. People just comply!
Pound for pound you’d likely be better off putting your energy into policy. The scale is still tilted there, but there is some traction behind fairer app marketplaces.
This is also why I do not use any of these platforms, instead having spent the time to rig up my own alternatives: Google-free AOSP-derived Android on mobiles and tablets, Linux on laptops and servers, Searx for search, Nextcloud for "cloudy things", NC Talk and Jitsi Meet for videoconferencing, Exim and Dovecot for mail, Peertube for video, Airsonic and MPD for media streaming, etc. I've been doing this since the late 90's of the last century (minus the mobile stuff since that simply did not exist back then...) so I can state with certainty that this is not just hollow rhetoric, it is a viable alternative to submitting to the whims of companies like Apple (et al).