I'm fairly certain that it's happening right now. There is no threshold that LLMs need to "break through" to see adoption. The number of non-technical using them to write software is growing every day.

I was working freelance through late 2023 - mid 2025 and the shift seemed quite obvious to me. Other freelancers, agency managers, etc that I talked to could see it too. The volume of clients, and their expectations, is changing very rapidly in that space.