For what I understand, the two most requested features for AD are: "select similar" and "vector tracing". In my opinion, these two missing features are very different for what concerns impact on the workflow and difficulty of implementation.
"Vector tracing" is usually something that you do once, at the beginning of your work, when, for example, you want to transform a hand-drawn logo in to the rough vector sketch of what will be the final product. There are other tools, even online, that can do the job quite all right, so this is not killing too much the workflow of many users. Moreover, I guess this is a functionality that requires a lot of work to implement, so I can quite understand why it's not there in the software yet.
"Select similar", on the other hand, is something that, if you use it (for example for editing CAD-exported graphics or geographic maps), you use it all the time, not just once at the beginning. You might have to select tens or hundreds of little vector elements scattered all over the drawing, and that's just too painful to do by hand. So, not having this feature, is definitely destroying the workflow of some users. And for what concerns the implementation, I am quite sure this is much easier to do than vector tracing. I mean, the objects are already there, they have their properties already assigned, it's just a matter of filtering them by stroke, color or whatever. So, I don't get why this feature is not implemented yet.
It would be interesting to have a clarification from the developers on why this highly-requested feature has not been implemented yet after 5 years.