As for why I prefer Sync, I love the consistent Material You theming and animations, the advanced filters that allow you to filter posts per keywords, the QoL stuff like automatically removing AMP links and preloading posts and comments in case you lose your internet signal, the inline link previews in comments and posts, the endless customization, that yeah, can be overwhelmed but also very comprehensive, and the excellent support that the app recieves, constantly being updated with community requested features.
Because I like Sync better and value is subjective. Besides, the dev is super responsive and active, Sync pushes updates very frequently with fixes and community requested features.
It's quite polished, mainly that. Even for a beta, there's almost no bugs, it respects Android Material You specs including animations, and it's highly customizable, allowing advanced filtering for example. It also adds very nice QoL features like automatically removing AMP links for full links.
Value is subjective, I personally consider it worthy of my money.
It has a ton of features and polish, and the UX is very good. Mainly that, value is subjective, but I'm willing to pay the dev for a good app.