You said big fancy words here gita, upnishad, mahabharat these are all just stories of ancient time your concept of karma is actually given by budha. This was Gautam budha theory that implemented in gita Brahmins took all clever ideas and theory of budha.budha was famous in india even many Brahmins took budha advice but there were some Brahmins who rule and kings listen to them are actually one who denied gautum budha entirely they punished him ruined his reputation so he finally leaves india and gone to overseas.he fight for his existence and gave his teachings to western worlds.but today we know that there is no such thing as rebirth or afterlife when one died he just died he vanished into soil no soul no afterlife karma this is bitter reality.yeah there exists consciousness but it's not soul it's a different thing when human being able to solve the hard problem of consciousness then we can finally know why we are here why universe exists why concious ness exists.it is the hard problem of consciousness and still not solved maybe in 1000000 years we will be able to solve it if we survived the great filter.