My recollection is that AltaVista had paid inclusions (paid links to be placed prominently in search results) in its search results. I think most search engines at that time did. So that the first AltaVista results page or two was rarely what I was looking for. So I did a a good deal of skipping past the product and service placement links to get to the information I was looking for.
Google appeared to be an exception in that it didn't appear to have paid inclusions, so I could usually start with something on the first page.
Despite all the hype surrounding pagerank, which continues to this day, Google's search results were not of noticeably higher quality (to me) than the alternatives. What was rings-around-the-competition better was how fast they were.
I used AltaVista back then and I clearly remember how much I hated it for being mostly useless. I was into data compression and wanted to find as much resources as possible, so I browsed through hundreds of pages of search results mostly containing gas pumps to pick up a couple of data compression articles. Google redeemed me.
I distinctly remember that my typical workflow involved searching on AltaVista plus another search engine. The advantage AltaVista always seemed to have was that it had a larger index than a lot of competitors. Often, the ranking was not especially good for obscure topics, so I remember I would often have to dig into 2 or 3 pages of results to find what I wanted. When Google came along, I would search AltaVista and Google. Google always seemed to require less digging that AltaVista.