1. It's not that easy to switch between providers. There's no lock-in of course, but once you build a bunch of code that is provider specific (structured outputs, prompt caching, json mode, function calls, prompts designed for a specific provider, specific tools used by the openai Assistant, etc) then you need a good reason to switch (like a much better or cheaper model)
2. All of these companies do try to build some echo system around them, esp in the enterprise. The problem is that Google and Microsoft have a huge advantage here cause they have all the integrations
3. The consumer side. It's not just LLM. It's image, video, voice, and many more. You cannot ignore that ChatGPT can rival Google in a few years in terms of usage. As long as they can deliver good models, users are not going to switch so quickly. It's a huge market, just like Google. Pretty much, everyone in the world is going to use ChatGPT or some alternative in the next few years. My 9 year old and her friends already use it. No reason why they cannot monetize their huge user base like Google did.