Lemmy's development compared to Piefed is quite slow. Piefed reached feature parity with Lemmy only one year and a half after starting, and now it has a lot more features.
Feature fragmentation happens all the time, Mastodon didn't have quote replies for a very long time, most of the Misskey forks had it.
People who want to use those features move to the platform which supports them.
Every time someone posts that a feature from Lemmy is missing while it exists in Piefed, people are going to tell that person to migrate to Piefed.
And it's okay, quite a few people probably don't need a "gore" filter or personal feeds. But for the ones who do, the option is there.