What is currently consided to be a good softwaret language or framework to use to make a UI?

I am writing simple console apps in C#. But I would like it if I had a good UI to use. Since we live in an age where everything is run off the internet or intranet through a web browser, should I use a javascript frame work? What is a good choice for that? If I am using the UI to access and upload local files, like excel data files, what would be a good suggestion to use? Is there a bare-bones javascript suggestion that I can use?

There is a lot of talk online that WPF is not a good choice anymore and is losing popularity and support. Is it being replaced by something like Blazor?

What is a good choice to make for user interface development if the middleware/backend has been already developed in C# ?

Hi,
I don’t believe WPF is going anywhere, and is certainly fine for personal projects.
You could also use Winforms.
With those two, you can design your UI inside Visual Studio, so you can get it up and running without worrying too much about the XAML or HTML/CSS.
Blazor is great but a bit more involved.

IAmTimCorey has some good videos on C# and the various frameworks.

Hope that helps