Your second source doesn’t say what it’s measuring and disclaims itself as from its “‘experimental era’ — a beautiful mess of enthusiasm, caffeine, and user-submitted chaos.” Your first link only measures chatbots.
ChatGPT is a chatbot. OpenAI sells AI models, including via ChatGPT. Among chatbots, sure, 84% per your source. (Not “90%+,” as you stated.) But OpenAI makes more than chatbots, and in the broader AI model market, its lead is far from 80+ percent.
TL; DR It is entirely wrong to say the “market share of OpenAI is like 90%+.”
[1] https://firstpagesage.com/reports/top-generative-ai-chatbots...