I've heard that great upgrades came with the latest release Unity 7.6
The latest stable version of Unity is 7.7 (as of December 2022).
But that up to day still has version 7.5.1 – how could I update to 7.6 or is it better to wait?
There are reasons why Ubuntu repositories do not have the latest versions of all packages. Ubuntu 22.04 will never receive the Unity 7.6 update.
A quick search in packages.ubuntu.com shows that Ubuntu 22.04 has Unity 7.5.1, Ubuntu 22.10 has Unity 7.6, and Ubuntu 23.04 comes with Unity 7.7.
So, if you want to use the latest version of Unity, try Ubuntu Unity Remix, which is an official flavor of Ubuntu beyond version 22.10. Version 22.10 will lose support in a few months, so I would suggest you to try the most recent version, 23.04. However, 23.04 is not an LTS version, and will be only supported till Januar