That's not in conflict with what I'm saying. Costs centers require a certain amount of investment to ensure the business runs efficiently. If you under fund it, the results are often catastrophic. However, if you over fund it (as in, put in more money than is needed to keep things working properly), there's generally no additional positive impact on the bottom line. So, from the business side, your main goal tends to be to find ways to keep cost centers running efficiently with less money... without inviting disaster.

Old, under-performing and flakey switches do have a negative and potentially disastrous impact on the business, but if you replace the network with "gold-plated" high-performance 100GbE switches, you're not likely to see much more upside than if you just had properly sized and maintained switches.