About the original issue, why don’t just ask for simple queries to look at page-tags too when looking for a reference?
Simple queries are already an abstraction with user-friendly niceties and they already mix pages and blocks in their results.
So your suggestion would be an additional shrewdness that maybe the developers didn’t think about.
About “unify pages and blocks” I don’t see how it is related to the issue above.
I suggest you to ask for something like “smooth out differences between pages and blocks”, that is something that could make sense.
But in this effort of smoothing out differences I don’t see room for changing the references methods, i.e. namespace(s) of pages and IDs for blocks.
I think you should specify what you are trying to accomplish as end-user before proposing a change like “unify pages and blocks” that for me it sounds like a technical solution without a motivation: exactly the opposite of what we should discuss in this forum i.e. starting from end-user needs to eventually arrive to technical proposals.