Here are some thoughts that might be helpful/interesting.
1. Natural selection only "cares" about how good you are at passing on your genes. By that metric, all species alive today that are maintaining or increasing their populations are equally "advanced" or "evolved." I don't mean to imply that there is nothing uniquely advantageous about the human combination of intellect, mobility, and dexterous fingers ... we excel at remodeling the environment to suit our needs, and making tools that let us beat other creatures in one-on-one fights. BUT, other species have other survival skills that are working out great for them. Natural selection has not favored humans over bacteria; our package of talents is not inherently more "fit."
2. Life is diversified to fill available niches/roles. We humans aren't necessarily here to exploit more resources than bacteria; we're here to exploit *different* ones. I happily coexist with the billions of bacteria in my house (setting aside pathogens for the moment) because they have nothing I want, and I have nothing they want. I actually create a lot of great microbe habitat just by existing, at no cost to myself.
A horse and a finch have no quarrel, because they occupy different parts of the available space and they eat different things. The horse is bigger and consumes more calories, and maybe horses as a population have a higher cell count (say they do for the sake of argument ... I don't know), but this doesn't mean that finches would have any incentive to evolve into horses. They'd be abandoning their current food base of seeds to compete with all the existing horses for grass. Why do that? However, if there are food sources that no one is currently using ... like seeds that are hard to open ... finches might have an incentive to develop specialized beaks to get at them.
3. Being at the top of the food chain actually tends to reduce the total biomass of your species. With a few unusual exceptions, all life on earth is ultimately powered by energy from the sun, which plants (the producers) use to make nutrients. Every time something eats and digests something else, energy is lost in transfer. So the more layers away your food source is from the producers, the less total energy there is for you to exploit. Have you ever thought about why none of our traditional farmed animals are apex predators? We *don't* usually eat lions -- we prefer to feed on the lower layers -- and one reason is that it's more efficient. And some people think that if the human population keeps growing, we'll have to reduce the amount of meat eaten per person to avoid starving. We could sustain more humans if they were all going straight to the producers for their energy.
4. When humans directly compete with some other life form, we can end up wiping that life form out. E.g. we extirpated the large predators who competed with us for livestock/game from large swaths of the earth. And yet, more recently we've pushed back on that trend and elected to repopulate some of our competitor species for aesthetic or moral reasons. It's like we also care about our *quality* of life and aren't just interested in reproducing and eating as much as possible. Weird.
