They are similar only on a superficial level, at their core they have not only vast differences in terms of how they work but they also have a different philosophy. It is not a matter of what you can do in terms of features, but also how you do it and how that affects the IDE, which is a core element of VB6 as opposed to VB.NET where you could be using whatever text editor or IDE you want (it isn't a coincidence that VB6 has its own IDE whereas VB.NET is using the same IDE as C# and C++).

VB6 isn't just the language, if anything the language is a minor part of it. VB6 is the entire tool, including the language, IDE and library. You cannot separate these, they are written for each other. This is also what pretty much all VB6 alternatives get wrong as they try to reuse elements designed for something else. You cannot do that and get something like VB6 beyond at a superficial level (and this is exactly what Microsoft did with VB.NET).