There isn't. There are exactly three independent browser vendors:
- Google with Chrome. Chrome dominates the market to such an extent that Google pushes through its internal APIs as "standards"
- Apple with Safari. They flat out refuse to implement many of Chrome's shenanigans, and also have issues with priorities and funding
- Mozilla with Firefox. Much like Safari, they are increasingly refusing to implement Chrome's shenanigans. But Firefox is rapidly declining in relevance, and will be on the brink of extinction within a few years (it already has at best ~150-199 million users)