Because it's not affordable. Also, solar panel production is not environmentally friendly or ethical, they last 10-20 years, then end up in a landfill forever. Stop trying to make solar happen
Here da ting do:
If we spend more money for R and D of solar panels we could probably make them less expensive and longer lasting and one day we could also see those theorized window solar panels which would be really good if they were long lasting.
Just think about it, in about 20 years of real electric car development we have already made everything the same or better compared to gas cars. Just imagining me what 20 years of solar panels development will bring us to.