The AI Models Index keeps tabs on premium releases from 15 top labs since 2023,...

https://rileysnewcolumn.readspirex.com/posts/why-does-gpt-5.2-cost-more-than-gpt-5.1

The AI Models Index keeps tabs on premium releases from 15 top labs since 2023, verifying dates and using blind-vote checks for accuracy. Updated every two weeks, it shows that new models now come out every 4.5 days on average—a 56% faster pace