Chamath predicted that if existing trends continued, the 2024 Republican primary would effectively become a two-way race between Donald Trump and Vivek Ramaswamy.

What actually happened:

• Vivek Ramaswamy suspended his presidential campaign on January 15, 2024, immediately after the Iowa caucuses, where he finished fourth behind Trump, Ron DeSantis, and Nikki Haley. He then endorsed Trump and exited the race. (theguardian.com)
• In Iowa, the first contest, Trump won with about 51%, DeSantis came second, Haley third, and Ramaswamy only fourth with about 7–8% of the vote. (en.wikipedia.org)
• In subsequent major contests like New Hampshire and through Super Tuesday, the competitive dynamic was Trump versus other establishment-aligned candidates (mainly Nikki Haley, with DeSantis earlier), not Trump versus Ramaswamy. Ramaswamy had already withdrawn and earned no delegates beyond Iowa. (en.wikipedia.org)

Because the race never narrowed into a Trump–Ramaswamy two-way contest—Ramaswamy instead exited early after a weak showing—the prediction did not come true.