To be fair, ES6 was huge. ES7, and probably ES8, are tiny by comparison with only a few new features. Once browser creators get caught up on ES6 it _shouldn't_ be too hard to stay caught up after that point.
But, most of experimentation isn't around the core ECMA features. The experimentation is happening around the toolchain, the libraries, the frameworks, etc. which are separate from stuff like ES6.
But, most of experimentation isn't around the core ECMA features. The experimentation is happening around the toolchain, the libraries, the frameworks, etc. which are separate from stuff like ES6.