Their build systems may do basically the same thing, but I bet they all do it dramatically differently and probably for good reason.
Every company you listed has different products, resources, deliverables and goals. Their build systems will have evolved over many years to take advantage of those resources and meet those needs, and that process will naturally lead to different solutions.
Every company you listed has different products, resources, deliverables and goals. Their build systems will have evolved over many years to take advantage of those resources and meet those needs, and that process will naturally lead to different solutions.