It doesn't seem like the extra traffic is the issue. People don't want Google's AI from reading and summarizing their data and thus preventing clickthroughs. Why would I click on your site if google did all the work of giving me the answer ahead of time?
Both are an issue. People don't want AI overviews cannibalizing their website traffic. People also don't want AI bots spamming their website with outrageous numbers of requests everyday.