No, that's how THIS planet works...you are assuming that this planet is functioning "correctly".
Of course and of course.
You are taking a very Earth-centric point of view, as though there is no possibility of any other type of planetary system out there in the universe.
?? No, I am taking the view that Earth works correctly. Io works correctly, even though its surface is a combination of airless vacuum and molten lava. Europa works correctly, even though its surface is completely frozen.
The only "incorrect" way a planet could work would be to violate the laws of physics. So far we haven't found one that doesn't, and indeed it is unlikely we will.
And now back to the original question, who is to say that "we", based on predation pushing evolutionary advancement, are the "right" life form to evolve?
We're not "right." We are merely successful.
This is not about being "lucky" to be alive, or if humans would or would not be here without predation...that would be to assume that humans are the "best" thing for this planet...and I am sure we can all agree on that subject.
You are using a lot of terms that indicate personal preferences from your point of view. "Right?" "Best?" Not really any such thing. (Indeed, if you are using the term "correct" as a moral judgment, as opposed to merely something that works correctly per physical laws, that would also be an invalid personal moral judgment applied to a physical process.)
Predation is a ubiquitous and powerful agent of natural selection. Is it is driven by a lack of resources? Probably. Where do the resources come from? The environment.
Exactly. And every organism without any limits on reproduction will continue to reproduce until those resources are exhausted. (Think yeast.) When that happens, they:
1) all die. This has happened millions of times in closed environments here, and has undoubtedly happened in the larger world as well.
2) die off enough that the resources can replenish themselves (if such a thing is possible.)
3) become prey for another species, and thus return to equilibrium (google predator-prey cycle)
So, imagine a different solar system, with a different energy source on a different rock with a different environment - think that life on that planet evolves from predatory behavior or not?
I imagine there would be time, very early in the existence of life on the planet, where there would be no predatory life. That would change quickly as the organism evolved to use all available resources - including the resources inherent in other organisms.