Why do people keep assuming that 21:9 is superior and it gives you better situational awareness? Yeah it might be true in games like CoD or Battlefield, that are generally played on a flat map... could even say that they're basically 2D games, since you cannot really move up or down and no enemies will approach you from that direction either.
Dreadnought is kind of a 2.5D game, as the maps have a relatively flat layout and your ship cannot turn on the Z-axis, but they do allow you to strafe vertically. I don't think either 21:9 or 16:9 is better here, and would definitely not call one superior. Maybe 21:9 is better for planetside maps, but 16:9 is better for deep space maps.
21:9 may give you increased horizontal viewing angle, but at the cost of vertical angles. 21:9 is a ratio, therefore the :9 part does not mean that 16:9 and 21:9 have the same display height, with the 21:9 only being wider. Ofc it is wider alright, but also shorter.
A 16:9 32" display actually has a bigger screen area than a 21:9 34" display. Another thing people get wrong is, that they usually upgrade from a classic 24" 1080p display, and go for a 34" ultrawide, then experience vastly increased FOV and identify it as a singular benefit of the aspect ratio. That is wrong however, since most of their improved experience comes from the greatly increased screen size itself, not the ratio. A 32" 16:9 display, having the exact same point-per-inch value (i.e.: same pixel size) as a 24" FHD display will have a horizontal pixel count of 2560. That means you can still get increased FOV, by 640 pixels (compared to 1920), in case the game supports it.
Ofc if the game is actually FOV locked, then everything will just become bigger, instead of letting you see more of the same-size things... but since it's a FOV lock, all aspect ratio displays are focked all the same.
For example I myself own a Z321QU, and have never felt it putting me at a disadvantage in games, though I'm not a CoD player, I give you that. I enjoy having a big 16:9 display, it's quite alright for gaming, and beside that, for my work it is better than the ultrawides.