I think you can. Fantastical creatures are literally assets easily associated with fantasy because culturally they are used extensively. The average non writer can recognize if there is a dragon, its probably a fantasy. Popular trends with dragons are fantasy media. Similar to seeing testubes in a room and thinking, this is probably a science laboratory.
However, this is not the be-all end all. I personally consider the culturally depicted aliens as fantasy not scifi even through it's liberally accepted since there was a trend of media that changed the culture. Conspiracy theories, startrek, ridley scott alien etc...
I think assets are just assets. You can use them to connect to audience culture, but it really comes down to presentation and experience. I think a few deeper levels would include...
-Fantastical landscapes (architecture that could never reasonably sustain but just do),
-languages that aren't organized but somehow just work, ---events that could never fit into the cause/effect rhyme of reason.
Definitely underutilized core values I would like to see explored in mainstream fantasy trends. They do exist as grounbreaking or original but trends are always based on safe ideas that already work.