I'm not sure what screen you're referring to. Perhaps the admin content list? Typically content producers will add content via the "add content" link/button (depends on your theme), edits are possible from any screen where the content is displayed.
Drupal supports a number of rich text editors, TinyMCE is only one of them.
As a rule, if the CMS puts you away from your page and to a list of "posts" to edit with TinyMCE, it's not modern. Atleast in my book.