In this case, you should know that the phagocytic model of endosymbiosis has been radically upended since the successful culturing of a Lokiarchaeota in (ecto)symbiosis with a delta-proteobacterium in 2019 by Imachi et al.
"Isolation of an archaeon at the prokaryote–eukaryote interface" https://www.nature.com/articles/s41586-019-1916-6 doi.org/10.1038/s41586-019-1916-6
The striking images of the branching, filamentous prokaryotic Lokiarchaeotum grappling its metabolic partner resembled nothing I had ever seen in biology before, save maybe the mycorrhizal root nodules of a legume at a ~2000x smaller scale. The prevailing model of the process of eukaryotic endosymbiosis is now "entangle-engulf-endogenize", rather than phagocytosis, which might be a secondary post-mitochondrial lifestyle adaptation.
If the Nature paper is difficult for you to read or access, this summary is well written and provides better citations than the Quanta article.
"Challenging Eukaryogenesis: The Story of the Eukaryotic Ancestor" https://arxiv.org/abs/2008.06608 doi.org/10.48550/arXiv.2008.06608
If you are interested in this topic, I cannot praise Nick Lane's nonfiction trilogy of books on mitochondria and evolution highly enough:
• "Oxygen: The Molecule that Made the World" (2002)
https://www.amazon.com/Oxygen-Molecule-that-Made-World/dp/0198508034
• "Sex, Power, Suicide: Mitochondria and the Meaning of Life" (2005)
https://www.amazon.com/Power-Sex-Suicide-Mitochondria-Meaning/dp/0192804812
• "The Vital Question: Energy, Evolution, and the Origins of Complex Life" (2015)
https://www.amazon.com/Vital-Question-Evolution-Origins-Complex/dp/0393088812