I wouldn't characterize it as forcing to "open up". It's true they put an end to some of the most egregious anti-competitive practices, but the Chinese tech ecosyatem, including payments, is still notoriously non-interoperable. For example, there's no way to transfer money between WeChat Pay and Alipay.
The relationship between Tencent/Bytedance/Alibaba is what happens when there are no monopoly laws or they are ineffective: every company fighting tooth and nail to corner every market with a single "super-app". No specialization at all and many races to the bottom, like the recent war between Alibaba, JD and Meituan over instant delivery that made every company involved lose a lot of money.