My claim is that it is essential, and if you don't properly industrialize before running out, you will never reach the stars.

Not really, because of the time scales and distances involved.

Doubtful those civilizations would get even close to STARTING on any interesting technology w/o cheap, plentiful, energy dense, non-renewables.

My claim is that it is solved for us, in particular, because we had a cheap, plentiful store of very energy dense non-renewables to bootstrap our technological industry from.

The question is, does that mean that is (or forms a significant portion of) the Great Filter?

I think it does.

My claim is that no civilization will develop spaceflight w/o those cheap/plentiful stores.

I'm talking about developing a rocketry program from nothing, not late in the program. That is literally where the filter has the most effect. Even getting to LEO is extremely expensive from an energy perspective. And getting to the point where you can actually use renewable fuels requires technology that simply would never develop without a large scale industry, one that likely could never develop without burning hydrocarbons to start with. And IMO charcoal alone isn't going to cut it.

You're going to expend enormous amounts of energy creating methanol if you aren't refining it from a non-renewable source.

That energy stored in chemical bonds has to come from somewhere. Not only that, you have to walk before you run, generally starting with solid rocket fuels.

IMO no rocket program is going to get off the ground (literally) w/o a plentiful non-renewable hydrocarbon source to start with.

Exactly this. If you run out of cheap energy before you get to the point of being able to sustain technological advances with renewables, your civilization is doomed. My claim is unless there is a cheap, plentiful store of non-renewable sources of very dense energy, no advanced technological society will ever emerge.

The path to the technology of getting mass to escape velocity is relevant. You don't just get to methalox or hydrolox without the previous steps. And the latter two energy storage mediums (in their chemical bonds) require an enormous amount of energy to actually create those bonds you're going to break later to extract the energy you put into it.

It has everything to do with energy. You have a gravity well to escape. That takes energy.

Cheap enough to get *any mass* into orbit. Including enough ejection mass and oxidants to get itself off the ground.

Do the math. Calculate how much energy it takes to get zero mass to escape velocity for various fuels (the mount of energy varies on the energy density and specific energy of the fuel itself).

I'm specifically referring to the *development of a rocketry program* which most definitely started with gunpowder for good reason.

The amount of energy required to get out of any significant gravity well isn't something you can just "wait" to form, unless you're literally talking about hydrocarbon chain ore deposits that took hundreds of thousands of years to accumulate.

Not going to happen without an energy source. Getting out of any significant gravity well isn't going to happen without hydrocarbon chains to bootstrap a rocketry program.

The earliest chemical rockets did not use aluminum based fuels. They were all based on hydrocarbons because they're cheap, plentiful and above all, did not require much energy to make them suitable as propellant.