It’s impossible to trust any sources these days because there are hidden agendas. […] No amount of “scientific literature” can contradict actual, basic, fundamental science about who we are and what we are supposed to eat. Anyone who does has an agenda.

Sounds more like, “I don’t like it, so it must be an agenda”.

If you have issues trusting science we won’t come to an agreement here. Having a biased view and choosing what you want to believe, despite contradicting evidence, is building an illusion and not having an accurate picture of reality.

Note that research on that topic has not just popped up in the last couple of years. Also you may take a look at other cultures for hands-on counterexamples, e.g. some monks who live and have lived their whole lifes without consuming animal products.

The fact remains: we are omnivores

I wonder how you decide what a “fact” is, since you have issues trusting the work of scientists.
Anyway:
The fact also remains that digestion capabilites, i.e. being able to eat both plant and animal matter, don’t necessarily impose dietary recommendations.

What you need to survive is a set of nutrients your body can digest. In which form they come, is less important.