Let's imagine a user journey:
User makes a request and then there's text, no ads (for now) no links to get you out of search page. So where does Adwords get triggered if there are no linked events? Then advertisers will see a drop in traffic because Google is literally giving the answer instead of making people click to search. This will accelerate the cycle of reducing ad spending, which will make things more difficult for Search. Then SEO marketers and basically all the web industry around Google will see a massive impact as well, because they cannot "optimize" anything that makes people click. The main problem is the dependency of Google on ads (60% of revenue). I see Bard as a negative downwards trend that will decimate the company even further.