Would you briefly explain the use of the following wish in different perspective with various examples please?
I would say that "Thank you very much" is slightly more formal than "Thank you so much."
The two are synonymous. No one would really blink at one being used over another, but usually most people would just say "thank you".
The latter one sound more childish
Wow, dad, thank you so much!
(Eventually with emphasis on so)
I would certainly use the former, although the latter is probably accepted in common speech.
I only the construction so [adjective] in conjunction with that. Someone can be "so hungry that he could eat an elephant," but not just "so hungry." In the same manner, the latter seems to be thanking the recipient so much that… and the reader is left hanging.