Again, you neglect the third option: someone who wants to send bitcoin but also wants to embed “arbitrary” data (which is, of course, not “arbitrary” to them, but essential, based on their subjective value of the data).
nostr:nevent1qqs2cn6pjg49ldhc4ptgm7e0c83ttmm527qzgawev03h5w3sgjhdtecpz...