If you are frustrated by Blogger feeds that are too short, there is some rescue.
Feeds are broadly useful ways to share your blog posts, and I make use of feeds in some of the tricks in this blog.
Unfortunately, Blogger keeps messing with them.
In 2011, Blogger started paginating its feeds at 500 posts. The entire feed was still available, but in chunks.
You had to hack the url parameters to get the whole feed, one 500-post segment at a time.
Recently, Blogger ratcheted that down to a mingy 150 posts per chunk, a real pain in the neck for some of us who have been cranking out blog posts for a while.