The number of feeds available from topic to topic varies and depends in part on how many websites both rank highly for a search term and have a feed available.
Not all websites allow their content to be syndicated, so those that don't will not have a feed for the software to find.
The software limits how deep into the search results it looks on PURPOSE.
While if the software kept scraping into the hundreds of pages of search results it probably could find more feeds, they would be low quality, non-authoritative feeds that are not going to provide the authority boost you are looking for for your own content.
Please think intelligently about your topic and expand to nearby similar topics in your searches if there are not many feeds being returned.
For example, if you are trying to rank for "curling irons" you can expand to "hair styles" and "fashion" since they fit in the same general topic sphere.
If you are trying to rank for "Halloween", try expanding into "holidays", "decorating", or even "home and garden"
Remember, you are not trying to bundle your content in a feed with exact match content that will COMPETE with yours, but surround it with complementary content that tells search engines you're worth indexing on that subject.