This.
Gemini Pro requires a monthly subscription.
Seems like a pretty straightforward business model.
How many would really pay though? I certainly wouldn't. Would you pay for Google search?
Their ads are very convincing, I'd pay up to 40¢ a month for Gemini to tell me how to recover with a recipe for tomato sauce I accidentally put sugar in, though only in months where I inexplicably add sugar to things.
They are also trying to reduce workers in search, etc, somewhat through the trained LLMs so the other idea is that they have lower costs per user.
I don't think many people will pay monthly fees or will want to pay them for each platform they use which is why they all tend to do so many questionable integration attempts to try to get users to not want to use a separate LLM of their choice in a browser instead.