Final answer:
The usage of distributed switching has diminished as the capabilities of backplane bus speeds and centralized switch fabric capacities have increased, allowing for more efficient centralized traffic management in networks.
Step-by-step explanation:
The use of distributed switching has decreased over the years because backplane bus speeds and centralized switch fabric capacities have increased.
Distributed switching is a method in which each switch makes its own decision about where to forward traffic, without the need for a centralized control mechanism. As backplane bus speeds and switch fabric capacities have improved, networks have been able to rely more on centralized switching, which can provide more efficient and effective traffic management due to advancements in technology that enable higher performance and faster data handling.
The increased speed and capacity reduce the necessity for distributing switching across multiple devices, since a single centralized switch fabric can handle larger amounts of traffic more efficiently.