One webmaster asked John during his hangout on 09/10/2021 about specifics on their e-commerce website. More specifically, about filter and search pages.
Their question was about their site, which has a lot of variants and search queries for many different products. They use filter pages, and these are optimized and indexable. But they don’t get indexed.
John explained that Google doesn’t try to recognize the difference between different category pages, filter pages, or search pages. Google sees all of these types of pages as being equivalent.
This happens at approximately the 32:01 mark in the video: