Most websites only explicitly deny scraping by bad bots (robots.txt). Things like Cloudflare are a completely different matter, and I have a whole batch of opinions about how they are destroying the web.

I'd love to compete directly with OpenAI, but the cost of a half million GPUs is a me problem - not a them problem. Google can't be faulted for figuring out how to crawl the web in an economically viable way.