On Twitter, Google’s John Mueller said that Google’s algorithms do not prefer large websites. There might be a correlation of large sites ranking better in Google but that is not caused by the ranking algorithm:
Correlation… I don't have statistics on that (& what is "rankings" anyway). Definitely no designed connection.— John ☆.o(≧▽≦)o.☆ (@JohnMu) 6. September 2017
John Mueller also said that a few awesome pages are better than millions of mediocre pages:
YES! Focusing on fewer pages can lead to #awesomeness. Any script can make millions of pages, only you can make great pages.— John ☆.o(≧▽≦)o.☆ (@JohnMu) 7. September 2017
More is better, though
The more pages your website has, the more likely it is that your website will rank for more keywords. If your pages have high quality, Google will rank them, no matter how many pages you have. Optimize different pages of your website for different keywords that are related to the topic of your website.
Google ranks topics, not keywords. If your web pages contain many keywords that are related to a particular topic, it is more likely that your web pages will get high rankings for these topic. The Top 10 Optimizer in SEOprofiler can help you to optimize your web pages: