Joplin has a WYSIWYG editor mode. https://joplinapp.org/help/apps/rich_text_editor
Joplin also can use external editors. https://joplinapp.org/help/apps/external_text_editor
By external editor I mean editing the markdown files directly without opening joplin app first. There can be many reasons to do that like editing in a terminal or auto generate/manipulate notes using a tool. We can still do it of required but we need to be careful not to touch the Joplin metadata.
PS: I use Joplin regularly. These are not complaints about Joplin, but just an fyi to help someone make an informed decision before they switch.