There is surprisingly little disagreement among nutrition experts. Comparison of guidelines around the world shows this while eliminating political biases in the US. The widespread belief (in the US) that nutrition science is not settled is the result of decades of work by the 'Merchants of Doubt'... basically the same folks that spread disinfo about smoking and climate change.

Read about the McGovern Cmte in the 1970s. Big Food saw what happened to Big Tobacco after the Surgeon General's report (a few years earlier), and acted swiftly to take over the McGovern Cmte, even to the point of the new Cmte retracting the earlier report! And we have been in disinfo land ever since... with paid food influencers (whose ideas you appear to embrace) being the latest distributors.

We did co-evolve with our foods (over millions of years). Since humans have essentially no major adaptations to meat eating, this suggests it was never more than a useful supplement to our nutrition. Relative to apes, our adaptations are to eating more starchy foods (enzyme overexpression) and cooked foods (reduced dentition, jaws and GI tract). These adaptations provide ample energy (glucose) for our much higher metabolisms and larger brains.

Human protein needs are rather low compared to many other animals (e.g. human breast milk is very low protein). This suggests that we are adapted to eating lower protein foods. Poor human health outcomes from eating excess methionine (common in animal proteins) suggest that animal protein was not the major source of dietary protein.