As long as WeChat is the only messaging app allowed in the PRC, it will be able to get away with far more than any other app. It doesn't make any sense to compare niche productivity tools to it.
Growing up in the early 00s, software used APIs without fear of rules being imposed after the fact, and without needing to become arbitrarily successful in an authoritarian regime the OS & hardware manufacturers deemed a key market.
There were also piles and piles of viruses, malware, and Adware.
I'm not defending this particular frustration of iOS App Store policy. But it's worth recognizing that there is a balancing act going on here. Apple and Google are in the difficult position of trying to balance reasonable security policy with people's freedom to use their phones as they want.
If there is a happy medium between where Word Processors are also virus vectors and the walled gardens we have now, I don't think anyone has found it.
