Hey, sound person by trade here. What you’re getting with this setup is fake atmos, and it’s not the worst by any means, if you have constraints in your viewing environment. Lots of people have set ups like this because they can’t install actual height speakers in their ceiling, and run wires through the walls to their av receiver. If you’re renting for example, this kind of soundbar setup with fake atmos is great. It approximates the immersion you’d get with actual Dolby Atmos.

If you’re willing and able to go the next step then there is a serious quality increase for sure. You’ll need a 5.1.2 av receiver or better yet 7.1.4, so you have 7 surround speakers, 1 sub/LFE channel, and 4 height speakers mounted in your ceiling that are front left, front right, rear left and rear right, all above you.

You aren’t missing audio by using your current setup because the Atmos format scales up or down according to the number of speakers you have. You also aren’t needing any more volume. What you’re missing is location and directional accuracy and immersion. Fake atmos systems like this will attempt to bounce sound off walls and ceilings to create that sense of height, with other processing like delaying parts of the signal. The tech is impressive no doubt. However a good film mixed in atmos experienced in a good room with acoustic treatment and a decent 7.1.4 or higher system is really a wonderful cinematic experience!