I don't know what the car market is like where you live, but where I live the majority of people only buy used cars (because of the lower cost). This is possible because of a surplus in supply of once-new cars. If we're going to get past the tipping point for electric cars, I'd suggest we'd need to see one of three things happen:
1. New electric cars sold at a price point that can compete with the used car market.
2. An increase in popularity in electric car conversions (whether DIY or done by a professional).
3. Wait until the early electric car models trickle down to the used car market.
We haven't seen how this will hit say, stuff like the bolt, but basically everyone but tesla got hit was outrageous depreciation.
If that keeps up, electric cars could become a similar price choice for a lot of people who don't need to drive all that far, even if they're the earlier low-range models. This could be further incentivized by stuff like free HOV access and free charging some places a lot of locations enjoy.