Traditionally, harming other people and the environment has made it easier to feed your own children (or at least the children of your tribe) and have more of them.
Evolution does not necessarily mean getting smarter or better in any way other than more adapted to the environment (natural and artificial). We could be getting stupider and more violent if that leads to hoarding more food and reproducing more in the given context. It's also not evenly spread throughout the species, some could be evolving various abilities while the rest are stuck in a plateau or even regressing.
Similarly with social progress. There is a common myth of linear progress through history, where humanity now is better than we were a century ago, a millenium ago, and ten thousand years ago. In some ways we're better, in other ways we don't even know what we've forgotten and lost.
What we want is conscious evolution, where we shape the direction that we wish to evolve towards. Unfortunately with the state of politics we've lost decades of progress in a very short time.
On an evolutionary timescale it's a bit early to call humans a success. We only diverged from other apes about 5 million years ago, and have existed in modern human form for much less. Mitochondrial Eve lived only 100-200K years ago.
In the last few hundred years since industrialization we've been destroying our own environment - the one we'd previously adapted to - at a rather remarkable rate, an "experiment" that is still playing out. Will it turn out to be successful, or will we end up modifying the environment so much (or just fail to evolve quickly enough to adapt to changes outside of our control) that in another million years we'll all be gone?
We'll certainly not last forever, even if we manage to have a run as long as the dinosaurs. Whether it's climate change, disease, or some unforeseen change in our fortunes, eventually we'll either go extinct or branch off into a bunch of other species that would be unrecognizable to ourselves.
I think that that might be an aspect of the reproductive fitness of the 'hive' (or meta-organism) of all humans, rather than the genes in any individual or population.
I agree individual humans mostly seem to behave more like single-celled micro-organisms and it's a stretch to call it a collective-organism, but it's also not impossible to see the relevant analogous aspects though I think! (like, the internet could be one example?)
It's an interesting question whether the human species (or life-as-a-whole?) viewed as a single-system will be able to reproduce itself. Sounds like the question only makes sense when talking about settling elsewhere than Earth.. Mmm, reminds me of the Fermi Paradox. Will we make it through this!?!
We are parasites in a sense. Parasites are far more common than symbiotes. It is much quicker evolutionary speaking to up and have a parasitic relationship than to have the far more many step changes to actually taper that parasitic relationship into a symbiotic one that doesn't kill the host off. Doesn't bode well for ourselves though, as this implies we need to get decimated by the climate crisis to pare down our population to the small subset that gives a shit about it and also is smart enough to adapt to or slow the process, and things would only get better once this population reseeds the planet.
That's the way evolution works - isolated sub-populations that mostly don't breed with outsiders necessarily diverge.
Of course evolution is essentially directionless, just "survival of the survivors", although over time whole ecosystems of co-evolving animals and plants will necessarily settle into dynamic "attractor states" of semi-stable co-existence, until a spanner is thrown into the works.
Because that isn't what evolution does. Evolution is the process whereby traits that make reproduction more likely under selective pressures become more common. There is nothing in that process that necessarily implies a lack of harm to each other or the environment.
Wars did become less violent, but the on scales of several hundreds of years. I'm not talking about industrializing death, but about desire of violence (civilian suffering, genocide). Evolution is very slow.