In some respects I think if there were a well defined "Typescript, The Good Parts" I would happily migrate to that.
I do wonder if there will, one day, be a breaking fork of JavaScript that only removes things. Maybe a hypothetical "super strict" might do the job, but I suspect the degree of change might not allow "super strict" code interacting with non "super strict" easily.
BiteCode_dev has provided a pretty good summary of a lot of the issues. A lot of them have easy fixes if you are prepared to make it a breaking change.
[0]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...
Around half of that list is things added later that were supposed to make the language easier to use.
I sure would like a real "Good Parts" series of books.