From my perspective your rock is all small pieces. I look for rock as big as possible anymore. A lot of people have to build their shapes to get the dimensions they seek because they have small rock and look for some special design. I just go for the natural look and like a full looking tank. With small rock and over time with coral growth the coral itself will out weigh the rock and then you see them topple over breaking. But that takes time. A long time to fill 24" of tank.
With this new, been around a while, look of no rock in the tank. Tanks look empty like you yourself are feeling. And if there is a lot of fish, or even a decent amount of fish, they need places to hide and sleep. I get a tank full of coral but there must be a base to support it. And time before its full. Sals corals are huge compared to yours and thus his tank looks great and over time will get better.
So either give your system time or decide to go smaller or different shape to make your coral look bigger or achieve that look quicker. Or make them grow faster.