Joost, thanks for your added thoughts.
In my courses, I use the "manual completion" checkboxes for almost every resource and activity (some resources URL
I have Moodle check). This is because for almost all quizzes, I allow "unlimited attempts" and therefore it is only the student who knows when they are done. Also, for forum posts, students can make more than the minimum until the due date, so again, only they know when they are done. And for Assignments, students can resubmit up to the due date, so again, only they know when they are done. In my one course, I have about 74 checkboxes!
The checkbox feature for Moodle is so important that I would ask instructors "Why aren't you using more checkboxes." At Moodlemoots, when students present what they like (and don't like) about Moodle, checkboxes receive positive comments. My guess is that some instructors (like myself at one point in time) don't use checkboxes because activity completion is not automatically enabled by Moodle. So having a feature whereby students can keep track of what they have done should be a fundamental feature of any LMS.
In my feature request, I am proposing that both Manual completion checkboxes and system-level checkboxes, be incorporated into Moodle 4.0. I even provided some "graphics" suggestions.
Yes, there are some settings in Moodle 3.11 to hide some of the big "Mark as done" boxes, but not for all situations. For example, if you use a URL Resource and show it on a new page, if you apply Manual completion, that big box will show itself regardless of whether or not you have hidden activity completion. And there are a few more "exceptions."
Yes, some themes might modify the checkboxes, but at this point in time, many of the popular theme folks don't have much to show because we are still waiting to see all the changes in Moodle 4.0. And why should we have to use a special theme when something is so important to core Moodle. Yes, you might say it is not that important, but Moodle's checkboxes have been around for many years (maybe back to Moodle 2.0 or so), and now they are being removed and replaced with a clumsy and inconsistent UI.
Well, some of this is the basis for the MDL-71856