> as soon as the Chinese manufacturers pump out millions of devices without it in the western market all at once, the developers will have to follow.

I highly doubt that. People have far too much money already invested in Play Store purchases, that's a lot to give up for a marginally cheaper phone.

There's plenty of users who never spend anything at all on the Play Store, the various estimations I see online are about 15% of paying users.

Also, I don't necessarily think the phones will be marginally cheaper, just that the market will adapt.