Depends on the default search engine. Many people went of their way to download a web browser that wasn't Internet Explorer for many years even though IE was the default.

If the default search were randomly assigned and Google investors were nefarious the investors (not Alphabet) could simply help launch 30 different subpar search engines. Then if a user landed on one of those as a default search engine: the user would switch to Google.

It would be great to separate the search index/engine from the ads and allow other search portals to pay for the index and choose how to monetize.

If google actually went about organizing the worlds information, that would be wonderful.