What do you currently use as a display? Is it 4k/HDR? If it's not, are you also planning to upgrade that?
Second, are you a big movie buff? Do you either currently have, or are willing to get UHD blu-ray's?
Here's my thinking:
If you are big into movies, and do have a 4k HDR display and either have, or willing to get UHD discs, then yes, Atmos will be awesome if you can get it within budget. If you're truly willing to spend, get dedicated speakers and a decent receiver.
If you are big into movies, have a 4k HDR display, but will not get physical discs, then be wary of Atmos since it is super rare to find Atmos via streaming. Just get 5.1/7.1 surround sound.
If you are big into movies, but do not have a 4k HDR display, Atmos will still be amazing as a way to slightly future proof your audio setup. However, in my opinion it would be hard justifying paying the extra money for the UHD discs purely for audio improvements alone. At the very least, if you do decide on Atmos, start thinking about getting an upgraded display at some point. In my opinion, I would get good audio now since that seems important and then save up to get a good display. Good speakers will last you a while and you can spend a year waiting for more mature HDR displays to release.
Finally, if you are NOT big into movies and really only care about games, just stick with a good surround sound for now.
Remember you can always upgrade your setup and it's a lot easier for audio. If you get great speakers now but only enough for a 5.1 setup, then later on you can always add additional speakers and a new receiver to get an Atmos setup.