It's been fascinating to witness the duality of Apple-related criticism.Are you implying that devs can ignore iOS because Android = 71% globally?
If so you are ignoring the realities of running a business. In several developed markets, Apple has a much bigger than 29% of the market.
Services like Spotify, Match etc can't just ignore 57% of the US market for example.
On one hand, people love to point out that Apple has only a very small market share worldwide and is at risk of being snuffed out by Android at any moment. Yet, as you so correctly point out, Apple's smaller market share belies the fact that they have aggregated the best customers in the world, leading to a user base that (often) spends way more than their numbers would otherwise indicate.
This is actually why I am not very concerned with the smaller market share that Apple Music possesses. I suspect that Apple Music usage is more prevalent in developed countries where iPhone usage is higher (and where users are more likely to pay the full $10/month). In contrast, Spotify likely enjoys greater market share in other parts of the world where android phones are more popular (but it also likely means that they make less money on subscriptions).
At the same time, Apple is constantly positioned as being one flop away from irrelevancy constantly (AI being the latest one), yet it has also gotten way too arrogant and powerful and is in need of government regulation to "save" Apple users from Apple itself. In reality, thinking that Apple users are somehow being forced against their will to buy products like Apple Watches and AirPods is nothing more than looking for someone to blame for market failures when the problem is found internally with a bad vision, inadequate corporate culture, and lack of understanding as to what makes Apple unique.
Personally, I am not too worried about this legislation because I don't think it will have a material impact on Apple's bottom line. Apple remains its own toughest competitor as the challenge is often in getting users to upgrade from previous versions of their products to the latest ones. It doesn't mean I agree with rulings like the DMA though, just because I think that Apple can easily absorb the costs from a business standpoint. This remains a violation of Apple's property rights, and if bad actors like Spotify and Epic want their victory, they will have to fight for it.
Let's see how Apple's appeal goes. Because an Apple that retains control of its own ecosystem is an Apple that always wins.