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.

Familiarity. I think that tops the chart for a lot of people.

Personally, the thing that the other apps don't do right yet, is the layout on big screens. On a foldable or a tablet Sync looks way better than the rest and I have tried them almost all. Connect is the closest one on a regular phone.

Interface, usability and features fit for my needs, that's all the benefits I need.

Features I like for my clients are

• simplified, but decently designed UI
• setting to show uncropped images/videos in posts and comment view
• dark mode (adaptive colors syncing with device theme and color palette are a nice to have, but not mandatory)
• shortcuts to formatting options in Editor (list, bold, italic, code, citation, etc.)
• color setting to highlight OP or self in comments, links and other stuff for better information parsing
• feature to easily minimize comment threads

Sure there are a few that satisfy some or all of these, but you have to take into account personal taste as well. No one will buy a banana with perfect nutritional values, when it tastes like tobacco.

There isn't a one-fits-all solution, just try them out and stick with what fits you best.

For now I completed the client speedrun and chose Sync, but I'll give Boost a try when it releases, since I used them before, but as soon as Infinity hits the store, I'll probably return to that, Docile Alligator created the perfect mix of simplicity, usability and visibility for me.

Multi windows, ability to cache comments are the biggest ones at least for me. Imagine desktop class multi tasking and not having your comments/posts reload because you were low on ram,etc. Smoothness is subject and I find other clients like Jerboa more smoother overall.