The embedded mini-app ecosystem is a real model in China. Wechat being the most popular platform. Douyin also has a good share of it. You even see such ecosystem in payment apps like Alipay. I'm also certain there are special deals with Apple structured around this concept.
ya - i think the replication of the wechat super-app has been attempted so many times in the west at this point, but maybe agi coding solves this...?