I'd say that this is not a very meaningful question.
There are still tons of companies running IBM 3050 (?) emulators on 360 emulators on newer systems because the software has been running and stable for decades and the source code was lost a long time ago.
Delphi was really popular up until D7, when they made some changes that caused several popular component libraries to stop dead in their tracks, which is why D7 is still popular.
The truth is, there are TONS of Delphi apps built in the D4-D7 time-frame that are still running today. I suspect a huge chunk of EMBT's revenues come from such companies who keep their licenses up-to-date just in case they need to hire some folks to fix things.
Last place I worked, they had a team of 8 or so Delphi Devs who all quit at one point save two new guys, who were their for another decade. I was hired to replace one who had recently left, and while I was there the other one left. They hired a new guy and transitioned another fellow over from C# who didn't have much trouble learning Delphi, then cut me loose. That facility was on track to be generating $1.5 billion in revenues this year. The entire facility is driven by software written in Dephi between 2006 and 2010. Management there has been trying to replace the Delphi code since 2014, and has refused to allow it to be expanded or extended or anything. It's still their most stable, most reliabe and full-featured platform in the company, and they can't just shut it off without losing hundreds of millions of dollars of revenues. Delphi apps have become the platform companies love to hate -- they want to get rid of them, but they can't afford to.
For a decade now, the Delphi code has supported features beyond what their other platforms don't offer, and apparently can't offer. And the Delphi version has not had any new features added in TEN YEARS while the others have been under active development the entire time! Go figure! (They have had 30 devs working on the other platforms, and only two have been maintaining the Delphi code since 2014.)
Personally, it makes no sense to me. They've got a huge installed code base that's stable, reliable, and fully debugged. So why go with another platform where all of the code is new, will take a couple of years to get to where the Delphi version was three years earlier, and will be full of bugs for the next several years? Why not build the NEXT version in Dephi, re-use as much existing code as possible (reducing your programming needs to some extent) and save a huge amount on development costs? Like I said, Delphi is the platform that companies love to hate today.