Gemini 2.5 was the first breakthrough model, people didn't know how to use it but it's incredibly powerful. GPT5 is the second true breakthrough model, it's ability to deal with math/logic/etc complexity and its depth of knowledge in engineering/science is amazing. Every time I talk to someone who stans Claude and is down on GPT5 I know they're building derivative CRUD apps with simple business logic in Python/Typescript.