The OP writes that
In Obsidian, a tag is: “A connection from a note to an idea”.
But I don’t think following that idea is wise. Your ideas should be notes, not tags. The note itself is the idea and the source of its information / knowledge generation power. The tag is the meta category that the note can - without a second thought - be related to. ie a logical and uncomplicated broad based filter!
Fundamentally it comes down to finding a good way to use tags for what they’re good for, which is identifying shared qualities of notes across different topics - but not qualities that directly link notes together (ie relations - thats what links should be used for). This is why a lot of people advocate for using tags as “statuses”.
Another cool use of tags I considered was location / time specific identification. So if you did a semester abroad, your could tag all notes that you write in that time away with #semester-abroad. ie, stuff thats useful for filtering later, but that isnt based on filtering down by topic - because that will always get way too granular and take too much consideration (a larger note could potentially have 5-10+ valid topical tags)
I read also this article about topic vs object tags. People said it was good but I didnt understand it on first read (have no idea why the thumbnail is that weird dog 
)
In the end I would say that the style of using tags as broad based, cross topic groupings of notes (eg statuses #follow-up, timeframes #q1-2022, location based #semester-abroad or identifiers #meeting-notes) and using [[links]] as connections of direct bidirectional relationship mapping stands to bare the most fruit and take advantage of the power of obsidian in the long run.
Also keep in mind what kind of vault you are working in.
I have a technical reference vault for programming and there I only use tags as I want things to be very specific - and because its a technical reference doc, it is. So the tags then work as quick narrowing in on topics that are inherently specific.