Hi Gunnar-Haslinger. As called out, the Microsoft Store has no concept of latest version for packaged apps as compared to any other version. It maintains and can only provide a single "package" which is the most recent package published by the author. This package can in turn contain various versions as the publisher sees fit. This is all completely unrelated to WinGet and has always been the case. You can narrow down what is downloaded using certain filters like architecture, but not latest version. You'll have to review the metadata for each item downloaded to determine its applicability and choose from the there.
As for WinGet being a successor to the Store for Business, it's not, was never intended to be, and anyone claiming as much should be corrected. Again, there are limitations in the Store that WinGet cannot change and not being able to download or install paid for apps is one of them.
For license downloads, have you tried with a non-built in app?
Finally, I fully appreciate that doesn't directly address some challenges you may have, but WinGet can only provide what the Store allows it to. Along with the retirement of the Store for Business came some changes to the Store ecosystem. The best path I can suggest here is to not think of challenges in terms of how you used to address them as that tooling is now gone, but instead to take a step back and address the challenge itself instead of trying to recreate tooling or a process that no longer exists. Additionally, knowing exactly what the challenge is that you are trying to address, the "why" of what you're attempting to do, is helpful for us to understand how to help you best and to determine if there are actions needed on our end.