Google's John Mueller was asked if Google Search would be impacted if you block other crawlers, like Bing or the ChatGPT crawler. John said no, "Google doesn't care if you block other crawlers."
This came up on Twitter the other day, where the SEO asked, "if I block CCBot from crawling my site through robots.txt? Will it help in blocking chatGPT from using my site's content?" John replied, "Google doesn't care if you block other crawlers. I'm curious though, why would you block it?"
Here are those tweets:
Google doesn't care if you block other crawlers. I'm curious though, why would you block it?
— johnmu is a ranking factor and so are you 🐀 (@JohnMu) February 6, 2023
Yes, if you block Googlebot from crawling your site, that will have an impact. But blocking Bingbot, DuckDuckGo or other search engines won't impact Google, it just impacts those specific search engines.
Forum discussion at Twitter.