It’s not exactly surprising. ES6 came out almost 6 years after ES5, so there was quite a few changes then. The yearly release cycle was always going to mean fewer features being standardised each release.
While I do follow from a distance some of the work TC39 does, I can only assume that most people involved have realised that having an orderly process for feature proposals - and not trying to rush heaps of features into a single release - is a much better way to do things.
> With the language moving this slow compared to faster releasing languages like Python, Elixir, and Go
Python, Elixir and Go have the advantage that they have one main/reference implementation and can break backwards compatibility whenever they want (although that hasn’t gone brilliantly for Python) by just incrementing a version number. ECMAScript runtimes have to be able to run programs that were written almost two decades ago - backwards compatibility can’t be broken - and you have several major implementations (V8, Spidermonkey, etc.) to deal with.
The tail call feature from ES6 is already being revisited because it caused problems [0].
> I wonder if Node.js will start to see a decline in hype since the language hasn't improved much in the last 2 years.
Tools like Babel mean that people who really want to use new or experimental language features can do so. There are dozens of language features in the proposals pipeline [1] and many (if not a majority) can be used via a compiler like Babel or via a polyfill.
Node.js also has the advantages of having it’s own 'standard library’ and an enormous package ecosystem to use. I think it will be fine.
[0] https://github.com/tc39/proposal-ptc-syntax [1] https://github.com/tc39/proposals