How does the number of pages affect the SEO of an online store?

Question

Search Engine Optimization

Good day.
I am launching a new online store and, of course, I started studying competitor sites.
One of the main differences is the number of pages.
Being an adequate person, I want to protect search engines in every possible way from possible duplicates and low-quality pages that could be generated by CMS.
Therefore, I now (at the start) have about 200-300 pages.
Let's say that I write blog content for the site, add more products over time and create more category pages for low-frequency queries - the number of pages will double.
Competitors that rank at the top for the most high-frequency queries have between 3,000 and 1,000,000 pages in the index.
If you estimate the average by eye, it will be approximately from 4,000 to 18,000 pages, which is still strange.
Most likely, the fact is that these queries lead to sites of a wide range of subjects and they have goods not only from my niche, but also related ones.
Questions:
1) Where do the top online stores have thousands and tens of thousands of pages?
2) If these are duplicates, poor-quality pagination and filter results not hidden from the index, then why are they not excluded from the index?
3) What is the effect of such a number of pages on their SEO: positive or negative?
4) Should I also deliberately inflate the number of pages on my site if I have a rather narrow niche?
5) Why do general-themed stores win on high-frequency queries from specialized ones?
You say that to evaluate you need to look at competitors?
Google the phrase "buy a closet", "buy a bed" and so on, substituting any piece of furniture.
dmsky, mebelvia, mesto-mebeli and other general-thematic analogues win.

Answer 1

1. You need to decide what is a page and a product in your online store. For example, beds of different sizes or colors - are these separate pages or are these parameters already selected on the model page itself? And the competitors. This is where the difference in the number of pages can already go. In different topics, this can be both a plus and a minus (no one will look for the color of the bed - you will not receive low-frequency queries, but there will be a 6mm drill)
2. The number of pages, based on logic, cannot negatively affect the search, if all pages respond to their search query (thing brand model). If this is not the case, then only sections that answer general queries (bed, wardrobe) will be searched for, so here the number of pages is needed only for the assortment.
3. Search Engines See Range Width
4. Filters, faceted search from competitors can be indexed. From here, your pages can automatically be obtained. There are filters in the wardrobe section and indexed selections are obtained, for example: a wardrobe, a sliding wardrobe, a wardrobe, etc. in all respects. Theoretically, this gives an accurate answer for the search engine to low-frequency queries, but such pages may be of low quality or duplicated.
5. The number of pages on the site negatively affects the promotion because there is a search engine limit on bypassing the site pages per day. That is, it turns out that the site is indirectly re-indexed more slowly if you have made any changes or improved individual pages. Plus, here you can add "blurring" of search answers, because it is almost impossible to keep track of 100,000+ pages in terms of request-response consolidation.
6. Search engines give preference, of course, to stores (and sites in general) with a greater reputation (age, popularity on the Internet, assortment, click-through rate in search, time on the site). Ideally, there should be 10 large stores left on the Internet. And small ones worked only in narrow areas (not intersecting with large retailers)

Answer 2

I will try to express my opinion on this issue:
1) Most likely one of the reasons for the large number of pages is the presence of a search on the site that generates a new page for each request.
2) Provided that these generated pages are cannocical for the same Google, they are not duplicates. In addition, search pages can simply be closed from indexing
3) Given the realities of today, I would say that the influence is now exerted not by quantity, but by quality. Although I'm sure some will disagree with me.
4) Intentionally inflating the number of pages is definitely not worth it. Collect good semantics, scatter it correctly (as accurately as possible and without smearing) and you will profit. Keep in mind that the sites that are now hanging in the top are there not only because of the number of pages, but also for a number of other much more important factors.
5) If by general theme you mean aggregator sites, then they go on a common trust to the resource + relinking, etc. But again, this does not mean that you cannot bite off a piece of the pie in a narrower niche.

Answer 3

There is no direct connection between the number of pages and SEO