For what it’s worth, being a IG copy isn’t a bad thing. If they’re trying to get the IG crowd over, best to give the users something familiar to keep them using pixelfed. Having other apps is a nice feature for those like us who want it

Not that I use it often, But Pixelix on F-Droid has dark mode, and I do prefer it’s appearance compared to the official Pixelfed app or PixelDroid, that is just personal preference though

Not 100% sure if this is what OP was refuting to, but it is on F-Droid using the IzzyOnDroid repo.

https://f-droid.org/packages/com.hjiangsu.thunder/