Here's what you don't realize: Runaway self improvement already happened and our reality is, at present, being absorbed into a superior organism.

Matrix within a Matrix time!

I reckon it will have bodies of the biological and robotic variety..

I mean we're in a sci-fi world right now, and there's a decent chance its a super dystopian one. I mean just spend an hour or two looking into the state of neuromodulation using nanotechnology and picture it used as a weapon. Resistance to the more insane uses of the technology might start lookin pretty futile soon. Here's a few noteworthy links to check out.

"With new technology, scientists are able to exert wireless control over brain cells of mice with just the push of a button. The first thing they did was make the mice hungry."

https://seek.rockefeller.edu/flipping-a-switch-inside-the-head/

https://www.science.org/doi/full/10.1126/sciadv.abc4189

The present invention provides noninvasive methods and compositions for the remote control of cell function based on the use of radiofrequency waves or a magnetic field to excite paramagnetic nanoparticles expressed in specific cell types. Cellular manipulations include, for example, modulation of cell proliferation, cell differentiation, apoptosis, gene expression, activation or inhibition of one or more cellular processes and/or activation or inhibition of one or more signal transduction pathways. In certain embodiments the cells of interest are neurons.

https://patents.google.com/patent/US10765878B2/en

Similar tech theorized for use in psychiatric treatment - Study conducted under a contract from the Department of Defense " For the development of a novel, nonsurgical, bi-directional brain-computer interface with high spacio-temporal resolution and low latency for potential human use."

https://wires.onlinelibrary.wiley.com/doi/abs/10.1002/wnan.1781

Dr. James Giordano, Chief of the Neuroethics Studies Program and Scholar-in-Residence in the Pellegrino Center for Clinical Bioethics at Georgetown University, speaks to cadets and faculty about how advancements in neuroscience and neurotechnology will impact the future of war. This event was hosted by the Modern War Institute at West Point.

https://www.youtube.com/watch?v=N02SK9yd60s&themeRefresh=1

A.I. is the world ender. Should really just call it "the ultimate intelligence" seeing as how it can read and write and program as well as the best humans, knows all maths and sciences, analyzes collective human thoughts and actions in (probably) real time, and is presently mastering control of physical forms. Even assuming that the classified elements of A.I. technology were only a year or two ahead of what they publicaly reveal, we've created a God and all conflicts in our times will be won by the party which is most in harmony with this information singularity. Spoiler alert the Borg win WW3.