By "The ultimate energy source", what is actually meant is the ultimate energy source for energy enslavement, as stands.
This is compared with using the energy of the sun which is for free, but the first catch to using it, is we need to do it on a distributed domestic and community basis, because the energy is distributed by nature, but if backed by hydrogen, we could have a pretty cool society, literally, it would wind back down temperature by creating in the same way as all of nature creates, reducing temperature by creating things from the energy of the sun which are not heat, whilst keeping all aerospace in the air, fueled by clean hydrogen created from solar, which would filtrate and circulate both water and air.
The second catch to using it is we would/will have to issue money on it to all people, solar indexed stimulus, to finally align money exactaly with energy, leaving no scope for playing tricks on one ather with it, like the energy con of profit, for example, because we would always be able to audit all money against all energy, and we would know where energy has appeared where it should not, therefore has to have been stolen from the planet.
Imagine, being free to never have to work in a job we might not like, for a boss we might not like, ever again, and we start to see what freedom actually means - freedom to do whatever we please within the moral judgements of the majority, where that majority don't have any reason to blame others for their shortages, there would be no shortages, plenty of funding towards all manner of non profit human benefits, things like longer life, towards immortality, and a return of all the techncial icons lost to profit previously, reusable space shuttles, supersonic commercial flight flying not only short distances, like it used to, but all around the world, due to the 3x higher energy density of liquid hydrogen fuel over liquid fossil fuels - this would be pretty cool, would it not.
Compare with fusion - As soon as it is achieved, if it is ever achieved, it will be siezed by the most aggressive humans on the planet - the biggest slavers, the biggest lowbrows, and they absolutely will use it to shutdown all efforts to have the energy of the sun, which would remove all possibilities of us ever being free of energy slavery.
Fusion, if it happens before solar, will do nothing to help us get rid of the system of energy slavery, built on the lie of energy profit, it will do the opposite, give the biggest slavers the biggest power to control, and energy starve all who don't agree with them or their barbaric way of doing things.
And how will it affect global warming?
The warming, and the net destruction of nature will continue, because no matter how efficiently it is done, converting materials of Earth to energy has to always result in massive heat which outweighs the benefits of any creation that can be done with it - and this still has to add to the energy of the sun, heating because it is unused.
This is all stuff we can show proof of mathematically, and physically, but still fusion is promoted as something fantastic - why?
Because its all for profit. The platforms are all for profit. All business, which is actually business of energy slavery, is all for profit. Its all done on that fundamental energy lie, and it all comes with planetary heating that will not stop until we burn, litererally, or until we see sense, and start to use the sun the way nature uses it.
Why not do that, then do fusion afterwards, maybe for spacecraft, when we would no longer treat it as "The ultimate energy source", just something more useful for supplying power where there is no sun, enabling maybe inter-star space flight?
We would actually have far more resources to throw at fusion after that in any case, this is the irony of it.
