How does Alipay's user experience compare to Paypal's? Is it the lack of competition that has enabled them to expand their reach so widely (by not having to focus so much effort on each venture)? For example, the experience of shopping on AliExpress is (imo) sub-par when compared to most Western online shopping experiences I've had (Amazon, Zappos, and even smaller retailers).
I don't know a whole ton about the Eastern market to be honest, so I'm open to being educated.
I think it partially explains Alibaba's success in China. how you do shopping and paying is very much dependent on the "tradition" and regulation environment, and a local company can optimize that better than a global one.
Aliexpress is a mess though, i agree with that. But I think the language barrier faced by the shop owners there may be the biggest problem.
To your question "Is it the lack of competition..." I would say this is not the case. There has been plenty of competition. Alipay grew its adoption on its integration with Taobao in similar ways as PayPal was integrated with eBay.