Sometimes you just can’t fit a gallon of moonshine in a quart jar.

You have too much big furniture and too many needs for this small space.

You could eliminate the dining table and get one of those coffee tables that lifts up to dining table height..then put the bookshelf where the dining table is …next to the desk

I guess in Missouri moonshine jokes are common..and no one has to live in a studio apartment 🤦🏻‍♀️

Or a maybe just a tiny space?

You've done a good job with the layout. Is there any space under the windows to add storage ottomans. You can always use more storage.

How wide is the walkway between the sofa back and kitchen? You may be able to replace the dining table with a console table and stools which could also be a kitchen island, or back it against the sofa to look out over the living room. The sectional is so long, you may be able to fit two of them side by side.

What isn't functioning now for you? I don't know if it would buy you any space (if you need space somewhere specifically), but you could maybe replace the bookcase with a horizontal unit placed behind the sofa like a sofa/console table. Switch out the dining table to where the bookcase is now. That would allow the sectional to be moved toward the space left by the table a bit and give the dining table in its new space bit more breathing room.