Wish I could upvote and disagree. Evolution is a mechanism without a target. It's the result of selection processes, not the cause of those choices.
What is the purpose of declaring some organism the "winner" of evolution? This is like looking at a vast river delta and declaring one of its many streams to be the "most successful" at finding the sea. Any such judgement is epiphenomenal to the thing itself, which does not care about the stories anyone makes up about it.
Some people say that e.g. inner alignment failed for evolution in creating humans. In order for that claim of historical alignment difficulty to cash out, it feels like humans need to be "winners" of evolution in some sense, as otherwise species that don't achieve as full agency as humans do seem like a plausibly more relevant comparison to look at. This is kind of a partial post, playing with the idea but not really deciding anything definitive.
1Insofar as you're thinking of evolution as analogous to gradient flow, it only makes sense if it's local and individual-level I think -- it is a category error to say that a species that has more members is a winner. The first shark that started eating its siblings in utero improved its genetic fitness (defined as the expected number of offspring in the specific environment it existed in) but might have harmed the survivability of the species as a whole.
Yeah, this makes sense.
You could also imagine more toy-model games with mixed ecological equilibria.
E.g. suppose there's some game where you can reproduce by getting resources, and you get resources by playing certain strategies, and it turns out there's an equilibrium where there's 90% strategy A in the ecosystem (by some arbitrary accounting) and 10% strategy B. It's kind of silly to ask whether it's A or B that's winning based on this.
Although now that I've put things like that, it does seem fair to say that A is 'winning' if we're not at equilibrium, and A's total resources (by some accounting...) is increasing over time.
Now to complicate things again, what if A is increasing in resource usage but simultaneously mutating to be played by fewer actual individuals (the trees versus pelagibacter, perhaps)? Well, in the toy model setting it's pretty tempting to say the question is wrong, because if the strategy is changing it's not A anymore at all, and A has been totally wiped out by the new strategy A'.
Actually I guess I endorse this response in the real world too, where if a species is materially changing to exploit a new niche, it seems wrong to say "oh, that old species that's totally dead now sure were winners." If the old species had particular genes with a satisfying story for making it more adaptable than its competitors, perhaps better to take a gene's-eye view and say those genes won. If not, just call it all a wash.
Anyhow, on humans: I think we're 'winners' just in the sense that the human strategy seems better than our population 200ky ago would have reflected, leading to a population and resource use boom. As you say, we don't need to be comparing ourselves to phytoplankton, the game is nonzero-sum.
I think it's common on LessWrong to think of evolution's selection target as inclusive genetic fitness - that evolution tries to create organisms which make as many organisms with similar DNA to themselves as possible. But what exactly does this select for? Do humans have high inclusive genetic fitness?
One way to think of it is that all organisms alive today are "winners"/selected-for by that competition, but that seems unreasonable to me, since some individual organisms clearly have genetic disorders or similar which make them unfit according to this criterion.
There's some sort of consensus that we can assign individual organisms to "species", and then we could count it by the number of members of that species. Supposedly, the most numerous species is Pelagibacter communis, with 10^28 individuals, vastly outnumbering humanity. Maybe we could say that this is the selection target of evolution?
Of course as would be expected, pelagibacter is a very minimalist species, being single-celled and having very few genes. This minimalism also makes it hard to notice, to the point where according to Wikipedia, it was first discovered in 1990. (I wonder if there's another species that's smaller, more common, and even harder to notice...) This raises the question of pure numerousity is the correct way of thinking of it.
If we instead weight by biomass, most life is in the form of plants, and I think more specifically trees. This makes perfect sense to me - trees evolve from a direct competition for height, which is one of the traits most directly related to mass. And in a way, biomass is more sensible to weight by than numerousity, since it is less dependent on the way you slice a species into individual organisms.
But trees are pretty static. Maybe the problem is that since mass has inertia, this weighting implicitly discourages more dynamic species, like humans? An alternative is to weight by energy flow, but in that case, algae and grasses end up accounting for most of it. Sensible, because if you go up the trophic levels, you rapidly lose energy. That said, energy flow does have the dissatisfying (to me) element that it is "shared" between organisms that predate upon each other. I wonder if one could use something like entropy production to get a conceptually similar metric that's more attributable to a single organism.
I don't know of any weightings or metrics where humans are the winners, but it seems likely to me that there is one.