This historical monstrosity you wrote as a fact is hilarious. There is absolutely zero evidence for your claim of the Vedic people, who created the Vedas, buried their dead in fact the oldest written Rig Veda itself contradicts your claim. The prayers found in RV are still followed to this day when we cremate the dead.
Rigveda 10.16.1
"Burn him not up, nor quite consume him, Agni: let not his body or his skin be scattered." Agni means fire. Do a simple google search of the entire hymn and its English translation you will get your answer. I'm calling bullshit on your claims, sorry.
Secondly, during the Vedic period, the belief system of Indian and Iranic people was deemed quite opposite, for example, Devas are evil in Zoroastrianism while Devas are gods according to Vedas, Asura or Ahura as they call it are gods, while they are demons according to Vedas. The similarities are often contradictory. Just because Zoroastrians buried their dead, doesn't mean Hindus did too. In fact, we did quite the opposite, didn't we?
Now, I don't care about what Zoroastrians did to their religion in 2000 BCE, or how Vedic people practised their faith. Our fundamental religious text which is the Vedas does not have directions for humans. It is simply a collection of prayers, hymns, and rituals to the gods, later over hundreds of years post-Vedas, different customs were written down. We also don't follow the same way we practice in some 2000 BCE.
Note : There is no single point source for Hinduism hence no single point failures, Vedas were written over a course of hundreds of years, we adopted different customs like idols, temples etc mostly a post-Buddha, and Jain era customs, and we questioned our own religious texts, and critically reviewed them argued with different faiths at the time, adopted and adapted to the time.