There are. edX has an authoring tool called Studio. It's part of their open source platform, usually hosted right alongside their LMS, and pretty straightforw

There are. edX has an authoring tool called Studio. It's part of their open source platform, usually hosted right alongside their LMS, and pretty straightforward for non-technical users. Of course, the farther you go into building custom problem types (e.g. an autograder to run on student-submitted code), the harder it is to do things in that basic wysiwyg interface. Still, it's very powerful and opens up all the basics (video, text, simple questions) plus some very rich experiences like peer and ML grading. The original courses that edX hosted were authored in a rather tricky XML format. Authoring and QA in that system was time consuming for developers and borderline impossible for non-technical users.