Thanks for chiming in! I'll give it another spin, if I get some time.
If we take "rapid application development" out of its trademarked context, applying just its common-sense meaning, and applying it to the year 2020, then the modern tech ecosystem that one would want to integrate with is clearly not C++, but rather maybe JavaScript & the browser ecosystem, Python, and low-overhead JVM langauges like Scala or Groovy.
The next thing that immediately jumps out at me is that the form designer is still using pixel-based positioning, instead of layout managers and units of length that we know from html, like em (fontsize-based), or vh/vw (percent of view-height/view-width), etc.
I was trying to research these things more extensively just now, but giving you my name, street address, company, phone number, and then "Error: Field required: Yes, I would like to receive marketing communications" for downloading the COMMUNITY edition? Come on! Enterprise bloat: Check.
* Hit the installer and switched windows, to let the installer work in the background.
* Installer mysteriously gone.
* Tried to run the programme, and it took some digging to understand that the product seems to be in a half-installed state.
* Re-run the installer. This time, keeping the installer in the foreground. Now it works.
* Started Delphi.
* Dropped a button in the form designer to start playing around.
* Oh gosh. Form designer still using pixel-based layouts.
* Deleted the button.
* Doing some Googling to figure out how to do layout managers, and found an interesting youtube tutorial on something called TGridLayout.
* Dropped a TGridLayout on my form.
* Form Designer now caught in an infinite loop bringing up an Error modal that says "Control TButton($17EE2200) has no parent window. Path: ~TButton($17EE2200)".
Thanks Delphi! See you again, another 10 years from now.
> Oh gosh. Form designer still using pixel-based layouts.
If you build a desktop app, you'll get pixel-based layouts, because that's how Windows works. It is fully high DPI enabled and scalable, so it's not accurate really to call the units pixels. Call them design units or similar.
As you noted there are various layout tools, from containers with various flow behaviours, through to anchors and padding.