I'd argue installing more solar panels is way more important than EV's. It's way cheaper, offers way better ROI (EV TCO are just barely cheaper than gas, especially without gov incentives) and helps with main problem - power generation. Sure it's boring af, regulated, politicised (Uighur solar) and inconvenienced in every possible matter...
I think both are needed. Nothing on its own will work and we need to be doing everything that we can at the same time right now. The current models are showing if we make every improvement we can right now we are only just barely scraping by. There is no time to do everything sequentially.
A tax/higher prices on fuel would push people to more efficient methods faster and will put more money in to investments on new technology.