Google's John Mueller said on Reddit that higher page count "means nothing" for ranking higher in Google. He said, in fact, he has seen case studies from the SEO community where reducing the number of pages results in overall better rankings in Google search. But the number of pages on your site is not a specific ranking factor in Google.
John wrote:
A higher page count means nothing (otherwise everyone would have an infinite calendar on their site, or heck, two.) There's (still) no magical ranking factor that results in a site ranking better if it has more pages indexed. If anything, anecdotally from conference presentations & talking with folks, large sites that reduce the number of indexed pages end up ranking better (usually from cutting out cruft, merging similar content, etc). Of course, if you have more things to say about the niche that you're active in, by all means create more great content for it, but if you're thinking about just splitting your existing content out across more URLs, that's unlikely to be a good strategy for search.
An old poll from 2013 is where most SEOs believed that Google ranks large sites better than smaller sites. Although, how you define large vs small sites is a bit up in the air. Recently, John Mueller said that the frequency of content publishing also doesn't influence ranking.
Although, having more unique and quality content gives you more opportunities to rank well in search. But sometimes you can overdo it with the long tail targeting - I mean, Panda has come and stuck around.
Forum discussion at Reddit.
