There are no rapid UI dev tools anywhere that hold a candle to VB6. Winforms comes the closest. Web development is just a disaster area; I've tried a few things like Bootstrap Studio that try to get something like the ease of slapping together a UI with a visual designer that we used to have, but it is not even close; wiring up events is still laborious because of client-server and data binding, and CSS makes a mockery of attempts to have a WYSIWYG editor. Razor Pages looked like it might have been trending in that direction, but I am unclear whether that is still being worked on.
So I'm hacking away in a text editor, running a babel/webpack compile and bundle process that makes my Visual Studio solution builds seem instantaneous, firing up the app, hard-reloading the page a few times to make sure nothing is cached, then realizing I fucked something up or made a typo, and starting over. It's stupidly laborious and time-consuming. This is not progress.
That's true only for web development. Due to nature of web development is next to imposible to have a good RAD tool that can cover all use cases.
For desktop and mobile there are a few RAD tools. Some of them: QT Creator, Windows Forms, Delphi, C++ Builder X, Mono.
Maybe some are not of the highest quality and maybe there's not enough RAD tools, but that's because many people think that "true" development happens only in VI and command line.
As someone already commented, a good RAD tool can save 90% percent of the time because you don't have to connect by hand signals, events with handlers and you don't have to draw the UI by code, unless you need something specific. Doing this tasks is a tedious and boring work, takes time that is better spent doing something else like working on the app logic.
There is a VB6-like tool for the web! I know, because I co-founded it: https://anvil.works
I have ranted at length before on the reason that the Web is not amenable to RAD tooling. The short answer is that you have five different programming languages (HTML+JS+CSS+Python+SQL), with each component generating source code in another language, and that's impossible for a single development tool to manage sensibly.
To take one example: One of the best things about VB6 was autocomplete. But there's no sensible way to autocomplete what keys are in a JSON value that's been generated by a REST endpoint written in Python serving data from generated SQL, all with about 4-5 different frameworks in the way.
So for Anvil, we dispensed with that and did everything in one language (Python). Python on the front end, Python on the back-end, a Python-native database, a drag-and-drop designer producing UI components that are Python objects...and all of a sudden, it's all one representation and you can autocomplete it!
I place a lot of the blame for this stagnation followed by backward progress on the fact that a decent number of developers actually have a kind of quiet or even subconscious contempt for ease of use and RAD tools. "Real men" code by hand in a text editor. RAD tools are for wimps. As a result few developers work on them or use them.
It's sad because what developers are really doing here is wasting tons and tons of time. If we had really awesome modern and especially cross platform RAD tools the time savings would be enormous. We could spend that time working on more interesting stuff than wiring up controls to events.
