Standard-Toolkit VS lambda-converters

I don't know of any free control packages for WPF, although I'm sure they're out there somewhere. But I do know that WinForms has one called Krypton. It's open source and has a ton of stuff in it.

Yeah, I think some things go a bit too far. I also think they tried too hard to solve certain things (poorly) in XAML that frankly shouldn't be declarative. There's a few things you can do to make WPF less painful. I recommend using https://github.com/michael-damatov/lambda-converters, for example, rather than writing whole-blown converter classes of your own.

something like https://github.com/michael-damatov/lambda-converters should be built in because writing a whole-ass class is inexplicably verbose for 95% of things people do with converters

instead of full-blown converters in C#, let me write inline lambdas right in the XAML. Blazor lets me do that, sort of. (I use https://github.com/michael-damatov/lambda-converters so I at least don't have to write entire types.)

I haven’t dived too deep into MVU either, but at a glance, it seems more focused on lambdas. IMHO, one of the weak spots in MVVM/XAML is how much boilerplate you have to write for a converter, when oftentimes just a lambda would do. This lib helps, but it still isn’t inline with the rest of the UI.