It will either become paywalled or full of ads.
Personally, I don't think ChatGPT will start running ads in the next ten years. However, let's assume that it does.
Lmsys is for research, I suspect if it runs ads it will be like godbolt (a small ad from a relevant sponsor).
Llama 2 and 3 can always be run locally without ads. I make no claims about future versions.