In my job I am developing an app in C#. When I joined the team, there was already a Result library which is just a wrapper for return types with predefined set

In my job I am developing an app in C#. When I joined the team, there was already a Result library which is just a wrapper for return types with predefined set of result codes and a field for error message. It was first used for our bridge with JavaScript code, now it is used (and abused) everywhere in the app. I though it was a big PITA when I joined the team but I see the value now and I think the .NET ecosystem is lacking some standart way of doing this. Yes, there are exceptions, but we have a some states which are not "failured" per se and the Result library fits this well. The system is not perfect because the set of predefined result codes cannot be used everywhere and I am constantly thinking about how it could be improved. Does anyone have a clean way to do error handling in C#?