What your Wikipedia link says is already correct, ie that 3000BC is when kaliyuga started. The start of kaliyuga is not when the universe was created. Kaliyuga is just the last four hundred thousand years of a four million-year cycle, at the end which all the evil folk get purged and then the next cycle starts with a high quantity of good again.

The universe as a whole is created and destroyed in four billion-year cycles (one kalpa each). We're currently in the middle of the cycle, ie the universe was created two billion years ago. And Brahma the creator god lives for a longer time than that - three hundred trillion years - and we're halfway through that period as well.

Of course all these numbers are entirely "beautiful" mathematical constructions, and don't have any actual basis in observations or reality.