I do think D could have had a chance of upsetting or perhaps even replacing a lot of C++ usage except it had a couple major downsides in the past that stopped it (less so nowadays):
- Optional Garbage Collector, and being optional means that it’s not optional, as if it’s used anywhere then you are infected and the whole program scanning starts.
- Two major standard libraries, one leaned more heavily on the GC than the other (which was mostly or all GC free?). Nowdays one has already won out but it’s waaaay late for that.
The first is a MAJOR issue for C++ devs, the second was a complete failure as a usability requirement.
One big thing from the article:
C++11/17/20 novelties were first battle-tested in D
Ehhh, no, not really at all, rather they were "battle-tested’ in Boost for long long before D, in some cases for long before D ever existed.
And now Rust has better safety and reliability, even if not as many features, but those are things that exceedingly appeal to C++ devs, so I can’t really see D getting popular, much as an enjoyable language that it is, it missed its chance to shine due to those two big issues above in its past.