Another factor is that fossil fuels in general have high external costs not paid for by the user (like for pollution, health, and defense). Some estimates suggest these extra costs for oil add more than $100 a barrel for oil for US defense of long oil supply lines to the Middle East and a bunch in respiratory health costs (and also acid rain) for coal. When you factor in these external costs, renewables and energy efficiency have been cheaper than fossil fuels since the 1970s (see Amory Lovins' writings for example). This true cost advantage of renewables is true even if fossil fuels are free of charge or even negative in cost. If someone pays you $30 to take a barrel of oil, there is still this extra $100 or whatever of externalities per barrel that society pays. That is even ignoring any cost of climate change.
The only reason this uneconomic situation persists is extensive lobbying by the fossil fuel industry for subsidies and exemptions, so that they can socialize costs and privatize gains. If the fossil fuel industry becomes weaker financially, then its lobbying efforts will presumably also weaken. Then there will be more effective public calls for the true price of fossil fuels to be paid up front. And that will level the playing field -- and on a level playing field, renewables and energy efficiency will win big.
This is tangential, but it has been estimated (perhaps controversially: http://evnut.com/gasoline_oil.htm ) that more energy from electricity and natural gas goes into refining oil into gasoline than the gasoline delivers to cars. Thus gasoline is mainly being used as an energy carrier. Liquid fuels are actually good at that -- but you don't need a liquid fuel to be a fossil fuel. Or even a agriculturally-derived fuel. In theory liquid fuels can be produced from the atmosphere. And in any case, battery technologies continue to improve, and electric cars in most cases (except maybe cold climates) are better experiences to drive than liquid-fuel-powered cars regardless of fuel cost savings. If fossil fuels become unprofitable to produce and distribute, what happens to the gasoline station infrastructure required for gasoline powered cars? That would put a new meaning to "range anxiety" when a car driver could plug in to recharge anywhere but gas stations were few and far between. What is going on now is just accelerating ongoing technical trends -- which is perhaps why Tesla stock is still flying high (even with the recent tweet by Musk on it being overpriced).
Crude oil is more a battery than an energy source really given the energy needed to invest in refining it. Usually coal was the source historically for refining with some niche situationals like hydroelectric to save on power cost. Using "green" energy to export oil is older. Ironically if you have a refinery powering it by wind and solar isn't a bad idea given current power costs by source and can help reduce inputs required.
Are you saying that low oil prices are good for "green energy" since low oil prices motivates the use of renewable sources in the refinement of oil? First result on Google [0] says refineries "may use about 1.5% to 8% of feed as fuel". While a large emission source, in the grand scheme of things, converting refineries to use renewable sources seems less prioritised compared to replacing oil derived fules at the end user.
That shift however, will of course be less attractive in a world with low oil-prices. So in the end I think it's still hard to conclude that low oil prices are good for renewables?
[0]: https://pdf.sciencedirectassets.com/277910/1-s2.0-S187661020...