The view distance option in Minecraft defines how many chunks around each player are loaded. In the Minecraft client, this option is called "Render distance" and can be set to a lower value than the server's view distance to improve the client performance and FPS. However, it is not possible to set it to a higher value than the server's view distance to load more chunks. Setting it higher won't change anything.
Loading and generating new chunks is one of the heaviest tasks a Minecraft server performs and therefore loading more chunks has a huge impact on the overall server performance. That's why we have to limit the view distance to provide acceptable performance for everyone. Overloading your own server doesn't only impact your own server but also every other Minecraft server that runs on the same machine.
Increasing the view distance has an exponential performance impact because there are exponentially more chunks loaded. For example, with a view distance of 5, there are up to 121 chunks loaded. Increasing the view distance to 10 loads up to 441 chunks, that's almost 4 times as many chunks when doubling the view distance.
You can increase the view distance in the server.properties, but be aware of the performance impact. If you have performance issues, it is recommended to lower the view distance again.
Use Paper for better performance
The server software Paper has lots of performance improvements that reduce lags and allow you to further increase the view distance. That's why both the default and maximum view distance is higher when installing Paper on Aternos. You can install Paper here: https://aternos.org/software/papermc/
A higher view distance still impacts your performance on Paper, so make sure to test the performance and reduce the view distance again if you experience lags.
Fog in Minecraft 1.18+
In Minecraft 1.18 the client uses the server view distance which is why you see fog towards the end of the currently loaded area.
You can disable this client-side fog using mods like Optifine. You can download Optifine here: https://optifine.net/downloads
Just run the installer and select the Optifine profile in your Minecraft launcher. You can disable the fog in the "Options" -> "Video settings" -> "Details..." -> "Fog":
After that, you no longer get the fog and you can see the full view distance just like in previous versions.