No doubt your logic is based on the carbon footprint of two cars - the old ice and the new BEV.
Where that logic falls down is the old ICE becomes a more affordable efficient used car that can replace an older ICE that it blowing blue smoke. Further, new BEV become used BEV in a few years. Used BEV are becoming quite affordable and cost effective. They are also far outlasting their projected battery life.
Finally, demand for BEV increases R&D on more efficient storage technologies that are cheaper and have a smaller environmental footprint.
Yes, more and better public transport should be a thing. But the US is just too big - and in many cases too empty - for ubiquitous public transport to be cost or environmentally efficient.