Overall, the prediction that users would sort themselves into ideologically distinct platforms and choose services that reinforce their existing political views has largely played out, even though the specific forecast about Twitter staying left-leaning turned out backward.

Key evidence:

1. Clear partisan splits in which platforms people use (self‑segregation)
   A 2025 Pew study finds distinct party gaps by platform: Democrats are more likely than Republicans to use TikTok, Reddit, Bluesky, Threads and WhatsApp, while Republicans are more likely to use X (Twitter) and Truth Social. (pewresearch.org) This is exactly the kind of sorting-by-politics across platforms Chamath described.

2. Explicitly partisan platforms have emerged and become strongly skewed
   The same 2025 Pew data, summarized by The Verge, shows Truth Social is heavily Republican (6% of Republicans use it vs 1% of Democrats) while Bluesky is heavily Democratic (8% of Democrats vs 1% of Republicans). (theverge.com) These are concrete examples of people choosing platforms that “feed them what they want to hear.”

3. Twitter/X shifted from a Democratic-leaning to a Republican-leaning user base
   In early 2021, U.S. Twitter users were noticeably more likely to be Democrats than Republicans (about 32% vs 17%). (pewresearch.org) After Elon Musk’s takeover, multiple studies show a sharp realignment: Republicans now report using X at slightly higher rates than Democrats, and Republican users have grown significantly more positive about X’s impact on democracy while Democrats have become more negative. (theverge.com) That contradicts Chamath’s directional call that Twitter would stay a left‑leaning, coastal enclave, but it strongly supports his broader mechanism: users moved toward the platform whose political climate matched their views.

4. Facebook as ‘middle America’ with politically mixed but older-leaning news consumers
   Pew reports that Facebook news consumers are older than those on TikTok, Instagram, or X, and are almost evenly split politically (47% Republican/leaning vs 46% Democrat/leaning). (pewresearch.org) Perceptions of political content on Facebook lean slightly liberal overall, though Republicans in particular see it as mostly liberal. (pewresearch.org) This supports the “broad, middle‑America, older” user base idea more than a clean right‑only skew, but it is still consistent with his claim that different audiences gather on different platforms.

5. Political content and experiences differ sharply by platform and party
   A 2024 Pew report shows X is uniquely saturated with politics (74% of users see at least some political content, vs 52% on Facebook and less on Instagram/TikTok), and Republicans and Democrats report very different experiences and perceptions of bias on each service. (pewresearch.org) This indicates that platforms are serving distinct political information environments that align with user ideology.

Synthesis:

• Chamath’s high-level prediction — ongoing ideological self‑segregation by platform, with people gravitating toward services that validate their views — is strongly supported by the rise of explicitly partisan networks (Truth Social, Bluesky) and by clear party-based splits in platform use and experience.
• His specific mapping (Facebook = more right/middle America; Twitter = affluent, coastal left) is only partly accurate. Facebook is indeed older and broadly “middle America,” but not clearly majority‑right; and Twitter/X actually flipped from left‑leaning to more right‑leaning post‑Musk.

Because the central, forward-looking claim about self‑segregation and echo‑chamber platform choice came true in a strong way, despite some incorrect details about which side dominates which platform, the best overall judgment is “right” rather than “wrong” or “ambiguous.”