In practice Android is much more difficult to handle the myriad of offerings - Have you ever tried both? To your other point, what app spend would Anthropic be worried about - they have a subscription model.
They sell through the app, too. And Android users are just as unlikely to spend outside of apps as they are inside them. Android deprioritization is a business decision, not a technical complexity decision.
Please take a look at the percentage of paying Android users. It just does not compare. It's useless to count 2 billion users in third world countries who never have and never will pay anything in-app.
Users spend <25% as much as iOS users, and less than half in total despite larger user counts (having double the users who spend <25% each does not add up!), a gap that widens year over year. Why would they prioritize that?
Why would they care about prioritizing users who spend much less? Android pays <25% per user. You need a LOT more than 70% to make that worth prioritizing. Those users are just going to eat up free tier resources without paying. It's borderline parasitic from a business perspective.
Android users are more likely to be useful for spreading word-of-mouth reputation to Apple platform users, than they are as direct spenders. Just another reason to ensure Apple platform features don't trail Android.
Android is simply a much worse platform to make money on. Users spend <25% as much as iOS users. Why would they prioritize that?