Most often, I use tags to notate the item, not the tag, is transient. I use page links if that item has some relevant sticking power, if you will.
For example, recently I received two book recommendations. The first one came from a buddy whose enjoys reading so, for me in this context, that means relevant sticking power. They even provided a synopsis. That book gets added to my [[TBR]] page. Actually, I just dropped a [[TBR]] next to the book title that I typed on my Daily Journal page and I’ll move it on to the appropriate page in the next day or two.
The second book was recommended by a different friend. Their recommendation was, “Check out So Far From God by Castillo. I heard someone talking about it and sounds like you’ll like it.” That recommendation gets the #tbr tag.
I don’t want to psychologically manage a TBR page, with hundreds of off-hand book recommendations, floating around in the back of my brain. I can deal with 200 tbr tags (I don’t think about tags) but not 200 bullet points/check boxes (sometimes I can’t stop thinking about them) on my one TBR page.
The #tbr will not be going away but some of the books I append it to will, whereas most of the books on my TBR page will, ideally, be read and then transferred elsewhere in my vault as its own page. For me, the content is not cruicially important in determining tag v. page because both will appear in a keyword search, with page links being discovered passively and more frequently due to backlinks.