The official Android app is buggy (though it is beta), the content and creators are lacking, and it’s hard to find actual Pixelfed instance accounts for the things I want instead of a federated account from Mastodon, etc.
That being said, I’ve been using it for several months and like it. I’d be using it a lot more if it had more people and content and better discovery. FYI, I’ve long since deleted my Instagram account so I’m just patiently waiting for Pixelfed to pop off like Mastodon and Lemmy.