The site suffers from many ambiguous and misused popular tags, say 100+ questions. I'm hoping we can fix those, given the importance of grouping topics.
The reason tags become vague
By checking older discussions here, it appears to me that if a topic is a subset of another, retaining the main tag is the norm, and here lies the problem; that main tag only keeps getting more vague. The tag system of Stack Exchange was not designed for hierarchical usage.
The issue affects other sites. So for cohesion in working out this problem, kindly see MSE's related topic from 2010: How should ambiguous tags be dealt with?
The general solution to which is:
Generally speaking, though, yes, I think the way to go about this is splitting up the questions into >= 2 tags (as appropriate), and then blacklisting the original ambiguous tag.
Are there any issues with that approach? It seems to me it would put an end to broad tags, and achieve the goal of well-defined topics. In other words, to start favoring well-defined tags, e.g. What's the point of the tag [aircraft-physics]? That example shows that a popular tag with 300 questions would need only 10 or so actions to fix.