Wiki contains an "almost" WhatYouSeeIsWhatYouGet editor.
MicrosoftWord is closer to a WYSIWYG editor.
As you go from non-WYSIWYG to WYSIWYG editor, you make trade-offs. The trade-offs are not linear. In other words, some points along the gradient are a lot better than others.
[non - WYSIWYG editor]
easy to code, hard to use
\/
[almost - WYSIWYG editor]
ok to code, ok to use
\/
[WYSIWYG editor]
hard to code, easy to use
It's even more complex than that, as some tasks are easier on an almost WYSIWYG editor than on a fully WYSIWYG editor. See WhyWhatYouSeeIsWhatYouGetWorksNot.
And some tasks are easiest (and/or have superior output) when there is no WYSIWYG involved at all.