Exchange of value.

Websites tend to be okay with it because they accrue a benefit of Google’s crawling - they get traffic back. When websites don’t feel that Google keeps the traffic for themselves, websites tend to get upset https://www.theregister.com/2020/03/11/yelp_congress_google/

LLM training just takes and keeps all benefit to themselves. Wikipedia (or news site) get no traffic or anything back in return.