Oil isn't priced for the cost to get it out of the ground.
Oil is priced for the cost to get the last 5% out of the ground.
We don't have to replace 20% of the cars with electric cars.
You are right on the solar panels. We already have cheap solar panels. But the major industrial power plants have bought up every panel that will be made for the next several years. Until those orders are fulfilled, those less expensive panels won't flood the market.
Plus until we have better batteries, solar won't do more than demand shave (tho it's nice in sunny areas).
The peak energy most people can produce from their land/roof won't cover their energy budget. But it may reduce their energy budget. I have one panel that cuts $36 a year off my electric bill.
LED lighting energy savings beat that in six months. lol.
But net/net- my energy bills are down 30% now from five years ago. I simply use less energy than i used to.
Likewise, electric cars, hybrid cars and plain old gasoline cars with better gas mileage are all part of the total picture lowering demand for oil enough that prices were unsustainable.
and those trends are going to continue and get more efficient and less expensive.