Proton is a patched Wine with a translation layer from DirectX to Vulkan. Wine will run a lot of Windows cad software with varying success, particularly older versions and I am not sure how much general desktop applications benefit from the Valve sponsored improvements to gaming. It is a shame these CAD programs weren’t all built on game engines like Unity or Unreal instead of a bunch of Windows APIs with varied levels of implementation.
The biggest similarity with Windows is that it isn’t a community run project. In my opinion they tried very hard to represent themselves as an open source community in the early days and downplay Canonical’s role. There is nothing wrong with Ubuntu as a first introduction to Linux but if people are looking for a project to join and make contributions there are many better options.