Does fetch aggregate the logged time you've looked at the pages that you're now looking at to find the same page you found before and ruining all the results?
The search results are ranked by engagement, so yes, if you're currently looking at a page related to say python and spend lots of time on it, then when you search python on the extension, it will show up near the top. But what we've noticed is that the ratio of useful pages to useless pages in browser history is very high, and so when we rank by engagement, all valuable pages end up on top. Hope this answers your query.