Apart from the price, which should normally be 189€, it is a very good device.
It is not necessary as a device, especially for new televisions. But if you want perfect response without any lag, it is very good. However, if you have an older smart TV, it will give it a new life. Also, you must understand that "Apple TV" will support new versions for a very long time and you will never be outdated in terms of applications, etc. The storage space is more than enough because now all content is through streaming.
Another reason to buy it is the connectivity it provides. For example, an application called "infuse" which is essentially a media player (you can also use vlc but I recommend this one). I cannot go into great detail but if you know what SMB or NAS is, you will be satisfied with the mentioned application. You can easily test it because it is available for both mobile and PC. This application connects to the shared storage space (SMB or NAS) and at the same time recognizes the movies, downloads metadata, and provides a free "Netflix" experience. It downloads subtitles from "OpenSubtitles" if you don't have the file. If you can't find Greek subtitles, simply search for subtitles on another site on the internet, put them in the same folder with the same name as the movie, check if everything is correct, and nothing else. Just go to the living room, refresh the list with the press of a button, and continue as usual.
I now use this application on my computer as well because it is essentially a personal "Netflix" but with my own movies on the computer instead of the server that "Netflix" has.
The application is free but it also has a monthly payment of 1€ or a one-time payment of 100€. But you don't need it unless you want cloud streaming. That is, if you have a Google drive with 2TB of space and you have your movies there.
As for the sound, it gives you new possibilities. For example, I can have my MacBook and the TV playing a song at the same time. This can be a speaker but I don't know well about the speakers, the quantities, or if you can have surround sound (I don't think so).
As for games, there are some nice ones like "dead cells" and you can connect controllers. But there is also the "steam link" application to stream games from the PC.
The version with the new "thread protocol" is a must and it provides Ethernet as an additional port. Unfortunately, Apple has such marketing tactics that push you to buy the higher model. The device also functions as a hub, which is a must for smart homes.
If you are not in a hurry to buy, it is good to wait and get it for 219€ or even cheaper.