Yes you are right the eco-system is not as thriving as Go or Rust but personally I think these two languages are the anomalies rather than the norms perhaps due their godfathers i.e. Google and Mozilla.

Please do not write off D just yet since it's only about 20 years old. Remember when Python at 20, it was playing second fiddle to Perl, and Ruby was hot on its heels due to RoR. But now look how far Python has come despite the transition from Python 2 to 3 fiasco. At least D has passed the growing pain of transitioning from D1 and D2 with minimum damages.