Firstly, keep the reviews as they are. This is not a "completely revamp the Steam Review System for little or no gain, or even make it worse" suggestion. This is an addition, that also kinda tackles what the newest update with the language based filtering wanted to address.

So, currently you have a "yes/no" system (recommend or don't recommend) which is fantastic and better than any scalar system (like all the points and star systems) that are way too undefined (what a 8/10 is completely changes from person to person. Some throw 10/10 and 9/10 to any game they like, while others make a game 8/10 at best when it's not the best game they have ever played).

But the reasoning behind each review could be completely different. A negative review based on bad chinese localization is completely irrelevant to me. A negative review based on technical issues could be relevant for me but such issues could be leftovers from the release and be long patched, or even leftovers from early access. Maybe those technical issues are also to specific hardware, e. g. performance problems for Intel CPUs or crashes with Nvidia GPUs which would be irrelevant for me with a AMD pc build. So, I'd like to add an optional section when creating an review.

If you create a negative review, you get an additional section in the review creation menu. There you can choose from predefined tags what the problem is. Stuff like "Technical Issue", "Preferred Input Method/Device unsupported/lacking", "Localization missing/lacking", "Price inappropriate", "Gameplay", etc. These aren't the typical "areas" from those review templates some people use for their reviews with graphics, gameplay, audio, game size, etc, as this is not meant to make strange generic evaluations of all games that don't make sense for individual games. These tags should be designed/chosen specifically to represent the problems people can have with a game. That's why I would add "Gameplay" or "Content" or something as one specific thing that actually represents "This game isn't fun. Everything worked n stuff but I just don't like it" but would definitely keep stuff like "story", "graphics" and "audio" out.

Depending on what tag you have chosen, there could also be some additional info, like choosing "technical issues" could make a button appear like "add basic hardware information to review" that adds most basic information to the review like "CPU manufacturer, GPU manufacturer, OS". Localization could add a select element with all languages and maybe radio buttons for "missing" and "supported but bad". Input Method could show a select element with "mouse&keyboard, ps controller, xbox controller, switch controller, third party controller" and for vr games specifically the different vr headsets or their controllers.

You could also add a accessibility tag to positive and negative reviews, with a selection to narrow it down further (e. g. positive review -> accessible for blind people") though here people dealing with accessibility on a regular basis should be definitely asked here to make this actually helpful.

I'd argue this whole addition should be mostly optional, as creating a review should not be made more complicated for people that aren't interested in this.