I was a VB6 user back in the 90s, I think there's a bunch of reasons:

- Microsoft killed it: "let's rewrite the entire thing as VB.NET and make it completely different"

- The UIs designed in the RAD weren't particularly responsive in the sense of "responsive design" - generally you couldn't resize a window and have all the elements resize correctly. When I learned Java Swing and elements were defined programmatically as percentages of their container that was kind of eye opening to me.

- The small-time apps that were being developed with VB6 in the 90s are basically all web apps now.

Delphi and Lazarus are still kicking, the latter is free and open source.

I know you asked for "the language", but Object Pascal really ain't that bad to get around. If you were proficient in VB6, you should be fine adapting. :-)

There have been and are many, many similar no code or low code tools. And actually Visual Basic 6 still works.

What changed was the level of popularity and acceptance of those tools.

I think it comes down to trends and programmers psychologically subconsciously not wanting to be mistaken for users.

Because unfortunately what subconsciously is accepted as programming must involve colorful cryptic text. And if you are just dragging things around and setting parameters, you are not doing that, and someone might accuse you of being a user.

Not saying it makes sense, but that seems to be the explanation.

But look at WordPress, VB.NET, n8n, LabView, Unreal Engine, Houdini, Unity, etc.

C# with WinForms and Visual Studio was a decent successor for a while, but for whatever reason microsoft decided to go all in on XAML and then a bunch of other half baked frameworks. I have no idea what to even use anymore if I wanted to make a native Windows app, it's a mess.

You could try Lazarus + FreePascal or even Delphi

Have a look at https://anvil.works