The GC is realistically only an issue in rare fringe cases. Early on, the competing standard libraries were a massive problem, though. This was overcome with D2, which is already more than a decade old.

When this standard library competition existed, the library ecosystem had this very weird split where half of the libraries you would have liked to use in your project used the other library you couldn't link to at the same time. This prevented me from picking up and trying D for a long time because I didn't want to deal with that. Now that this is over with and a ton of useful libraries exist, I'm glad that I started to use D because this is now a language in which I'm very productive.