I think that the problem is that the modern web can “automatically” play content in a number of ways, and it is not possible for a browser to detect which are ‘automatic’ and which are you making a deliberate choice. So Edge can only claim to ‘limit’ it.
An option would be to turn off video entirely, so that it can’t play at all (like Edge does for Flash). I don’t think Edge offers that option.
(I’m using Edge. In Cafe Society, threads with linked video periodically burst into life, with all the video that I’ve viewed starting up again. Perhaps people over there are more likely to know something helpful.)
If this browser is on a computer controlled by your employer, they may well have eliminated your ability to get to those settings. One of the features of most MSFT end user software (not just Windows itself) is that it can be heavily controlled by the administrators of your workplace.
… one of the features of Edge (and Firefox), is that a lot of stuff has moved or just disappeared. Unfortunately, a lot of the information available on the web is (now), just wrong, as in this instance.
There are similar options in Firefox (with extensions that simplify the experience).
I don’t and won’t use Edge, so I can’t speak to the options there.