Everything has purpose for people that need it, and it doesn’t for people that don’t.
Markdown isn’t for writers, it’s for developers. You can’t bold or italicize when writing in console, so you use markdown.
Even Gutenberg has its purpose, as ugly as it is. It helps WordPress.com compete against website builders and against page builder plugins. At least that’s what I think, why Gutenberg was pushed down our throats.
Many bloggers (most?) hate Gutenberg because it completely changed UI/UX making it harder to simply write. Now they have to build a blog post, not just write it. This is akin to UK switching to driving on the right side of the road. Or US using metric system.
People are used to writing using TinyMCE because many text editors - online and desktop - conditioned users to this type of UI/UX to write. MS Word, Open Office, Google Docs, etc.
One thing to consider, since CP is business focused, business customers might expect to see TinyMCE because that’s what they used to and that’s what they use internally. This is just a thought, I don’t know if it’s valid or not.
And HAX, it’s quiet an annoying text editor. That toolbar always visible as you write right above is very distracting and it visually forces you into blocks. Having a border around paragraphs. The UI/UX is not intuitive, it’s asking me to waste time trying to figure it out. We’d be back with our own Gutenberg fiasco.
This was discussed before, and to quote James:
I wouldn’t replace TinyMCE in the core, but making it easier to allow a plugin to replace it if needed could definitely be something worth exploring.