There was a significant improvement with allowing developers to restrict features but you also need to be able to add them
It's a feature available on every editors integration. Draft, summernote, tinymce, ckeditor, and many others. Pretty basic stuff.
Theres a lot of content that you cannot insert, easily, without this.
References / footnotes, stock tickers, mathematics (mathml, mathjax, katex, ...) ..... I could lost an entire page worth the missing possibilities but I think you get the gist.
More importantly.... There are failing semantics without this. Ruby, proper demarcating edits, emphasis, language and directionality etc that could be added as useful utilities.
