It's nothing more than greed, just like the greed you supposedly fight against.
https://www.businessofapps.com/data/app-revenues/
> Apple Users More Willing to Pay for Apps
https://www.statista.com/chart/14590/app-downloads-and-consu...
> The median iPhone app user earns $85,000 per year, which is 40% more than the median Android phone user with an annual income of $61,000. [...] The average in-app shopping check is four times higher for an iOS user! [...] iPhone owners are also more likely to make purchases on their phones on a regular basis. These are important considerations for both retail app developers and those seeking to monetize via paid apps or in-app purchase. Mobile ads are the main source of revenue generation in Android apps.
https://buildfire.com/ios-android-users/
> Distribution of free and paid apps in the Apple App Store and Google Play as of June 2020
https://www.statista.com/statistics/263797/number-of-applica...
Denying business to your customers just because they're hostages of a greedy actor is not the best way to conduct a business.
The market is.
You can not afford not to publish something on iOS, if iOS were a niche platform used only by 1% of users maybe, but it is a mainstream platform used by more than 40% of users in the US.