It's important to actually read sources when it comes to controversial people and topics, rather than trusting some Wiki's summation of something. The Wiki completely misrepresents what Dr. Peat said.

"He made many other ridiculous claims such as avocados causing cancer.[8]"
https://rationalwiki.org/wiki/Ray_Peat#cite_ref-Vegetables_8...

Link [8]: "Vegetables". raypeat.com.
Goes to: https://raypeat.com/articles/articles/vegetables.shtml

The quote in question: "Not all fruits, of course, are perfectly safe--avocados, for example, contain so much unsaturated fat that they can be carcinogenic and hepatotoxic."

Note that phrasing "can be", "Not... perfectly safe.". Also btw, did you know that carrots "can be" hepatotoxic (toxic to the liver) because of all the vitamin A? This doesn't mean that carrots are bad, but rather that they shouldn't be an excessively large part of one's daily diet. They are not "perfectly safe".

Let's examine how Peat came to this idea based on the research. Remember, the actual claim is that "avocados.. can be carcinogenic and hepatotixic." Not that avocados cause cancer. That is not what he wrote. That wiki article has a clear bias.

Anyways, his research for the actual claim:

"In Vivo 1998 Nov-Dec;12(6):675-89. Comparative anticancer effects of vaccination and dietary factors on experimentally-induced cancers. ... Experiments in mammary glands cancer showed that a 15% olive-oil diet reduced significantly the tumor incidence caused by 9,10-dimethyl-1,2-benzanthracene. The antitumor effect of the olive-oil diet was connected to its content of monounsaturated fatty acids, such as oleic and palmitic acids. The promotive tumorigenic effects of other high-fat diets (avocado, soybeans) were associated with high content of some polyunsaturated fatty acids (linoleic and alpha-linolenic). Different diets have different targets. The effect of the same diet depends on its anti-tumor substances content. CONCLUSIONS: Vaccination and some diets have similar mechanism in their tumor-preventive effects."

"Ann Nutr Metab 1991;35(5):253-60. Effect of dietary avocado oils on hepatic collagen metabolism. Wermam MJ, Mokady S, Neeman I Department of Food Engineering and Biotechnology, Technion - Israel Institute of Technology, Haifa. The effect of various avocado and soybean oils on collagen metabolism in the liver was studied in growing female rats for 8 weeks and in day-old chicks for 1 week. In comparison with rats fed either refined avocado oil, refined or unrefined soybean oils, rats fed unrefined avocado oil showed a significant decrease in total collagen solubility in the liver, while there were no changes in total collagen, protein and moisture content. Chicks fed unrefined avocado oil as compared to those fed refined avocado oil also showed a decrease in hepatic total soluble collagen while hepatic total collagen remained unaffected. Electron micrographs and light-microscope examinations of rats' liver revealed collagen accumulation in the periportal location. This is suggestive of the early stages of fibrosis."

All he did was link real-world research to a possible hypothesis. A logical argument. Now you can criticize this argument and say that we can't draw any such conclusions from in vivo and animal model experiments, but at least then you'd be actually engaging with the content of the ideas, not outsourcing your thinking to a poorly-written Wiki article.