For myself, I began with GPT 4 chat which was very manual and needed tons of handholding. I stayed with OpenAI chat until o1 was removed, then started using GHCP. I mostly used Claude until 4.5 and got tired of how it would give 3x the code than was necessary. I noticed the new GPT's (>5) did the same thing as well; they both were addicted to bloating the codebase.
Due to that, I've been using Gemini since the golden days of free 2.5 Pro API access (privacy concerns aside...). I now use whatever the lightest Gemini model is for most things and hop onto Pro if I need a heavier lift. It isn't AS smart as Claude/GPT, but damn it can make things work with a fraction of the code and token cost.
My take: Anthropic and OpenAI are suckering everyone into making monstrous codebases they know nothing about, so they are dependent on the tools that will then cost even more due to the bloat. That, or the only way they are effective is to output so much, which I see as lesser than Gemini's ability to get more done with less.