I'd be curious to know which study you read, which gave you this information? Of all the studies I have looked at, an EV begins being cleaner than an ICE car in as little as just 8000 miles. For example, the Argonne National Laboratory in Chicago, includes thousands of parameters from the type metals in an EV battery to the amount of aluminium or plastic in a car, as a basis for the beginning of the comparisons to ICE vehicles.
Of note: Argonne's Greenhouse Gases, Regulated Emissions and Energy Use in Technologies (GREET) model is now being used with other tools to help shape policy at the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board, the two main regulators of vehicle emissions in the U.S.
They compared a Toyota Corolla (arguable a very fuel efficient vehicle) to the Model 3 and to summarize, if you were able to charge the vehicle from an outlet that gets its power from at least 90% renewables, the carbon break even point is 8000 miles. From that point on, you're cleaning the environment. If you got your power from coal, it would take almost 80,000 miles to reach the break even point. Either scenario still shows that an EV is much better for the environment compared to what you stated in your post.
Link:
Analysis: When do electric vehicles become cleaner than gasoline cars?