A global gasoline tax would hugely inflate the prices of good and services without doing anything to reduce emissions.

A gasoline tax that only affects private car ownership would have even a smaller environmental effect while negatively affecting non-urban residents pushing even more people into densely populated cities.

Ban on combustion engines (in new cars sold) isn't as bad as long as there an industry wide cooperation to provide an alternative, it doesn't not affect existing cars and services dependant on gasoline while providing a constant reduction in emissions as more and more zero emission vehicles are put on the road.