Coincidentally my steemit name is redgaruda so I felt really excited when I read your article!
I agree with you and believe that beings like garudas and nagas are much more than mere myths. There must be a reality to these mythological beings but this is a reality which is not very evident anymore nowadays.
It seems that the usual human consciousness is obscured in a way so it is unable to connect with these different realities and beings.
As you point out, it is not only hinduism or buddhism speaking about beings like gods and demigods (titans) but this is an element in almost all of the ancient cultures, including the sumerian, greek/roman, germanic and countless others.
We have to bear in mind however that these gods and demigods are relative beings like us humans with emotions like jealousy, anger, pride and attachments, when you read the greek epic myths, this point becomes very evident. These gods are extremely long living and powerful but not really immortal, omniscient or transcendent beings.
This is the reason why in buddhism, these powerful gods are not really reliable objects of refuge but spiritual transcendence is only possible through eliminating the causes of suffering and experiencing our real nature beyond ego.
Having said that, in the buddhist texts there are examples of gods, nagas and also garudas who have permanently transcended ego, suffering and delusion.
These deities are usually depicted with a wisdom eye between the eyebrows, you can have a look! In the case of garudas, they are called wisdom garudas.