You seem to miss the point being made.
No one wants to pigeonhole you. Rather enable you to find all the different groups that might interest your eclectic self.
A group not fitting any of the specific topics suggested would just be other as listed. One of the first groups I'd search through.
Or you could suggest a category.
It's not about importance it's just about practical ways to find all the groups that interest you.
You may love amateur radio but I'm neutral on it but forced to wade through group after group in the search for other things.
There is no doubt there are allready thousands of groups with many more to come.
It's unreasonable to expect people to wade through a single list for fear of missing a group they want.
I'm not judging anything. I just want a search method I can use without devoting days to it.
Practicality not ideology.