I found it hard to follow despite C# being my main driver.

Using ref, in the past, has been about modifiable variable references.

All these introductions, even when following C# changes across recent versions, were never something I actively used, apart from the occasional adding ref to structs so they can contain existing ref struct types. It never seems necessary.

Even without ref you use reference and struct types, where reference content can be modified elsewhere. And IDisposable for object lifetimes with cleanup.