You might actually be right. Even though I didn't use ninja, given their description a specialized build system for fast build that circumvents the problems the

You might actually be right. Even though I didn't use ninja, given their description a specialized build system for fast build that circumvents the problems they mention that make their build slow might be the solution. But are they not giving way not enough information to seriously assess their situation? That - combined with the shortness of your comment and that people could think it's a joke - would explain your downvotes.