The improved sandboxing model is supposed to be why this one's going to turn out better (and why it's worth losing some of the ease of development of the old ones...)
Silverlight lives on! i started in SL 1.0 and moved onto Xamarin and now to .NET7. Its the same code, same concepts, just different conventions around the APIs.
For me, WebAssembly is another target. ive been building webview based app UIs with (usually) native backends, cross platform for atleast 10yrs now. I still use libraries i made for SL because PCL was just the first evolution of dotnet! Life is good on the MS gravey train! Im running the same code literly everywhere, backend, frontend, UI, mobile, tablet, cloud. THE SAME CODE, just thin bootstrappers and OS specific impls of various services.
The best part of WASM i think is that i can write services in different languages, for specific purposes, if i ever need to. Yep, i can use scheme or haskell if the need fits, but c# has been evolving too and i can write functional anyways. Im not in the industry where a thin abstraction causes me scaling issues, but i am in one where its hard to find good devs, and usually they can read c# and pick it up quickly no matter their preferred poison.