The VB6 IDE... like the VB6 IDE... because the VB6 IDE...

The VB6 IDE looks quite simple to me. Perhaps that's why it is good.
But I mean, what's so hard to do? (It doesn't seem a too difficult project to me.)

IDK if "the IDE" includes the language parser, in that case, it gets more complex.

But what is particularly good in the VB6 IDE, besides its simplicity, is the Edit & Continue feature.
But... I think that must be more a feature of the compiler than the IDE.

You could say: "if this is 'easy' why nobody did it?".
Why would someone do it, if he's not going to do also the rest? I mean, the compiler, etc. There is no point in making an IDE alone.

10 years?
In 10 years my plans are telling an AI to make the program I want on demand, in seconds, using whatever languages it chooses (or invents at the moment, or just producing raw machine code).