If you work in dev/test/qa labs, there are a million reasons you'd need access to the BMC/KVM. It would be foolish to attempt things like firmware updates or testing the install of an upcoming release without it. Most modern BMC solutions also have a central management application that allows you to push firmware updates to all your hosts at once. And if you need to change properties like UEFI trusted certs, change boot from San parameters on the hba, or boot in legacy mode, you generally need "physical" access, at least the first time.
A decent KVM on an oob network can also remove the need to add jumphosts as an entry point to private testbeds. My job would be 10x as difficult without them.
This sort of device doesn't have that level of feature set, but even so, it could be very useful where I work, especially as it can power cycle systems or automate button presses with add-ons.