I would imagine that it's plug and play until you start adding nonsense like customizable scripting on buttons or more than a certain button count as is standard on specialized gamer mice, but sure, fair enough.
"This is a platform you can build on", software and hardware specs included, is still a much nicer thing to iterate on than "it's commodity parts to slap together" for someone without familiarity with the processes involved at scale, and going from "this is an opaque piece of hardware that responds on guaranteed timing" to "this responds on guaranteed timing but also has more complex features" is still a substantial jump, since "building software that meets realtime timing requirements" is not a thing in a lot of people's wheelhouse.
"This is a platform you can build on", software and hardware specs included, is still a much nicer thing to iterate on than "it's commodity parts to slap together" for someone without familiarity with the processes involved at scale, and going from "this is an opaque piece of hardware that responds on guaranteed timing" to "this responds on guaranteed timing but also has more complex features" is still a substantial jump, since "building software that meets realtime timing requirements" is not a thing in a lot of people's wheelhouse.