Alberto you might agree quoting one or two examples from nature is enough to prove possibility, but not the norm. If only part of the story is given to try to justify an argument, then at best it can only be a sales pitch, to sell a belief :)
If we drown, the actual cause of death is strarvation of oxygen to the brain, it wasn't too much of anything that actually killed us at all, it was scarcity, imposed by our environment, in the water. Of course a similar argument exists for plants.
Folk recognising your ad, know straight away you are trying to sell a belief, but do you yourself?
Have you noticed it is only the priveleged who seem to have that kind of belief?
In any scenario, competition for a limited amount of resource by a population of things that have to live by consuming it, a true zero sum game logically has to result in all dying. That is hard mathematical fact. The resource will simply dwindle until none is left.
But all of nature exists, it hasn't all died, so energy is not finite, only restricted, under certain circumstances.
We can work to increase the supply of it, increasing the amount that lives, or reduce supply, reducing the amount that lives.
We make the opposite choices there, it seems to me.