Visual Studio is kind of important if you want to use the SDK properly. But there's some alternative options.
Tutorials will all reference VS because that's the normal way of doing things, so not using it will make it more difficult.
First of all, and this is not optional, you must install the C++ build tools. This means that you either install Visual Studio 2022 (no need to use it, just install it), or the standalone Build Tools for Visual Studio 2022
Option one: use halflife-updated:
You cannot add new files to the solution since this requires Visual Studio to update the project files.
Compile via the command line:
path/to/MSBuild.exe path/to/projects/vs2019/projects.sln /p:Configuration=Release /p:Platform=Win32
Option two: use halflife-updated-cmake:
Cmake is complicated and requires extra knowledge to use.
Cmake replaces the VS project system with its own. When adding a new source file, you can use cmake to build instead of VS.