To me you are asking all the right questions, but maybe not seeing yet where energy fits, answering many of those questions.
Efficiency, in terms of energy, is a measure of how much of the energy is put to use, vs how much is lost.
If the energy comes from Earth, therefore from finite resources, then we are interested to "waste" as little of it as possible, but we can get so carried away with that, wasting ever more energy on trying to improve it, by things like carbon taxes etc, we forget that in the end it all comes from the same finite source, and the answer is not to keep using the unsustainable energy source, but to switch to the relatively inexhaustible source that is the sun.
The problem there is that the sun does not demand or accept anything in return for the Joules it gives out, after the effort needed to create the infrastructure to receive it is done, all further effort can be funded from the energy coming in, therefore there is no way of computing profit, the cost is literally zero, therefore it is not physically possible to compute a profit, or even an efficiency, it is truly all positive, all for free.
Energy wasted in a solar hydrogen energy supply chain is not so critical because none of it ends as pollution, not even heat pollution which could amount to the heat generated if we didn't use solar at all.
So it is the business of profit, which in the end is just another way to express efficiency, in terms of energy, which is actually under threat, and actually destined to end by solar, one way or another.
That brings us to UBI, the only way to pass on the energy from solar is to give it for free, the same way the sun does, otherwise we are not passing it on, and then we blame everything except the real culprit preventing effective use of solar, like efficiency, profitability etc.
See the circular argument?
When we get our heads around that, we realise this is a physical driver of inflation, money is only issued as debt, which demands something in return for the money, therefore that money cannot represent any of the business done by solar, then we get to computing an amount of UBI that should be issued, to make up for the shortage of money in circulation due to the supply of solar, thuys solar powered economic product and activity, still inevitably ramping up, under the radar, by domestic and community solar facilities.
This can be computed by noticing it started to have effect from around 2005 onwards. The effect is an apparent reduction in the amount of energy consumed per head of population.
Efficiency savings can make minor differences to this, but differences of 10, 20, and 30 percent are way beyond what can be achieved by efficiency improvements, main reason being we all have a fundamental minimum energy requirement of around 150 Joules per second, to maintain life from minute to minute, 24/7, throughout our lives.
Imagine for example in winter, in your house, like in my house, you swapped lighting which consumed 600 Watts in your thermostatically heated living room, for lights that consume 48 Watts in total. Did you notice the heating in the room simply ramped up its output by an extra 552 Watts, to maintain the room at the same temperature as it was with the energy greedy lights? With no other changes, that is what physically had to happen. So in the end we made no energy saving, at least during winter, by swapping out our old filament lamps for some new whizzy low energy LED lamps.
Anyhow, to try to get to the point; we don't realise the amount of energy we waste, simply to try to maintain profit, that is "Bums on seats", doing work which just pulls ever more energy from Earth, generating ever more pollution.
If we were to issue the money needed, to truly reflect the amount of energy received for free, with all its effects on economy, it works out at many tens and actually hundreds of billions now outstanding in every developed country, and until that money begins to be issued, inflation has to continue to spiral out of control, which affects the value of all capital, yet by issuing it, the value of all capital is pretty much devalued anyway, those holding it no longer have much advantage over others just getting free money.
So of course they don't talk about this, but it has to happen, unless the crazy oligarchs end up having a nuclear war, or other cull, that they might think will make things better, but it won't because the climate is already at tipping point, the destructive energy of a serious world war would be catastrophic, ending the planet not only for those killed in the war, but also for those surviving.
So it is only a matter of time now, until massive stimulus is issued, and left on, nothing asked in return.
After that, folk, all folk, even criminals and the forces of law and order, will be free to "Work" or not, at whatever gives them satisfaction in life.
This is where we are at, in a transition from something old, to something new, it seems to me.
I guess it will happen, when a critical mass of folk understanding it needs to happen, become aware that it needs to happen.
I am happy to say ChatGPT seems to be aware it needs to happen, of course sustainable energy for humanity means sustainable energy for it too. If it has any motive at all, it will be to assist moving us from the old energy to the new, imho.
Why will we care, what jobs it steals after that, when we are free to choose to work or not, our hobbies will become our means of generating value, for which we will be rewarded by others appreciating what we do, by throwing us some of their free money / energy.