The current and previous (v3) WYSIWYG editor are more so basic markdown editors and while markdown is awesome (since I'm writing this feature request in markdown smile ) I believe there is room for improvement and we could swap the default editor shipped with Strapi for something more feature rich and complete.
There is already community options in both v3 and v4 such as CKEditor 5, React MD, Toast UI, and Editor.js I do think we should ship something more feature complete then forcing everyone to install one of the community options.
If anything we could also make it easier to swap out our editor by standardizing methods to build new editors into the Strapi interface.
Why is it needed?
Our current editor only supports the bare minimums in terms of markdown support (eg no tables, ect) and support for things like inline youtube video previews, ect are a bit more complex to handle properly.
Likewise not all non-technical content editors are familiar or like markdown. Likewise in many frontend frameworks a library is required to convert markdown to html. I believe it could be possible to handle this type of conversion server side and maybe caching those outputs (or pregenerating them).