> I used this guide: https://docs.microsoft.com/en-us/windows/apps/winui/winui3

Your experience is expected for the framework. That thing is brand new, has questionable architecture, and I'm not sure MS will be able to fix.

The old and stable stuff is WPF (GPU-based on top of Direct3D 9) and Windows Forms (a C# wrapper around Win32, easier to use when you don't have a professionally-made GUI design).

> Visual Studio was too heavy for my 7th gen Intel laptop

VS2017 runs great on my old laptop with Core-i3 CPU from 2016. It's not the CPU. Ensure you have enough RAM, the system drive is a fast SSD with enough free space, and it's not a software issue like malware or an equivalent.

> VS2017 runs great on my old laptop with Core-i3 CPU from 2016.

For the last 1 or probably 2 years now I've been using VS2019 quite successfully on a 10 year old laptop with an i7-3520M (+ 16gb RAM & SSD).

Yes, its way heavier and clunkier than something like Eclipse for example and I do whinge a lot about how it loves to chew a lot of CPU and get a bit laggy when I'm typing code (why does Roslyn need 50%++ while I'm typing a comment? Is it really that interesting?)

But it is still useable nonetheless. The main issue I have with it is that touchpad scrolling in the code window really sucks and VS is really buggy in general needing restarts several times a day or things start getting 'weird'.

"Ensure you have enough RAM"? If a normal recent laptop might not have enough then the blame definitely goes to VS.

> Your experience is expected for the framework.

This is worded like a defense? But agreeing with OP that the situation is awful?

> If a normal recent laptop

Apparently, 80% of recent laptops are engineered for web browsing and very light office workloads, even regardless on their price. Despite the CPUs are generally good, they don’t usually install enough RAM in them. It started to change recently, half of the new ones have 16GB RAM which is good for development at the moment. But that wasn’t the case in 2016 when Intel released Kaby Lake CPUs the OP has.

> agreeing with OP that the situation is awful?

I looked at WinUI3 not long ago, and didn’t like it too much. I wouldn’t call the situation “awful”, but it’s not good either, neither for OP nor Microsoft.

The Windows GUI software I develop for living is often based on WPF. I think it’s superior despite much older: amount of bugs, quality of tools, binary size, etc. Fortunately for the OP, WPF is still supported in latest versions of .NET and Visual Studio, and is very likely to stay that way.

I guess I could use WPF but I want to build a shiny Windows 11 app using the new controls

Neither WPF nor WinUI are using OS controls for most of their GUI. Their GUI is defined by styles and templates in various XAML files. You can make controls look however you like. Microsoft did a great job back then re-implementing UX of WinXP and Win7 on top of WPF, but unfortunately not the newer Windows versions.

Here’s a third-party project with styles and templates implementing GUI similar to Win10: https://github.com/Kinnara/ModernWpf Their approach seems correct, and the screenshots looking nice. I never needed that library BTW, my clients who need good GUI usually provide professionally-made design which is unrelated to Windows controls.

Also, here’s a relevant GitHub issue https://github.com/dotnet/wpf/issues/5793 which currently says “.NET 7.0 milestone”, however the 7.0 is scheduled for November 2022, i.e. in about 1 year, and they may or may not deliver by then.

Developing .NET applications using simple text editors isn't really practical.

Everyone uses VS, Rider or VS Code.

Sublime Text is on par with VSCode. I wouldn't call it a simple text editor unless VS Code also fell into that category.

Does Sublime have a .NET plugin that offers intelligent, symbol based autocompletions (i.e. intellisense)?

I used VS Code but I still can not run my app. I can only use VS.

VSCode has issues with MSBuild for all but the easiest (read: Recent .NET version, targeting the web) to build projects. It'll be difficult to get by without VS unless you're a wizard, in which case you're probably stockholm syndromed into VS anyway.

VS has a debugger, which I find useful during development. Not sure if VSCode does.

Edit: looks like there is an extension for C# and C++

VSCode can debug and build apps if you have the extensions and tooling installed.

Even C/C++ apps. It's actually a pretty great visual debugger on Linux for that reason.