As "Observing" pointed out, saving time with oil changes isn't taken into account. If you can charge at home, saving time going to get gasoline is a big factor, also. I haven't been to a gas station in years. However, if you can't charge at home, charging is more time consuming than getting gasoline. Home charging or not is a crucial factor.
Also, Elon Musk has stupidly made himself and Tesla unpopular, so the cars depreciated more than they should have.
Lastly, as a more expensive vehicle in general, the insurance is bound to be higher for the Model Y.
So I believe in terms of yearly fueling and maintenance, especially if you can charge at home, the Model Y comes out significantly cheaper, and less time consuming. Insurance, depreciation, and the higher cost of charging at charging stations makes the bigger cost picture even out.