There are tons of information workers who are dependent on search in their work – or if they're not, could work much better with good quality search.

The examples are really too many to list, but it really depends on the person. When it comes to not spending a dollar, people will create the most incredible and reality-defying reasons. So I'd expect 99% of Google users to keep using Google, or maybe even stop using web search when Google becomes completely unusable. Then they'll say "I have no need to search for things anyway".