While true we are hardware bound, it’s pretty apparently we are not fully utilizing the hardware all the time. That gap is what research needs to close
I would say closing that gap is exactly what engineering is - optimizing your existing systems to maximally use the hardware. Its very quantitative and extremely detail oriented; you usually just improve Linux or add system calls for better performance, instead of baking up a whole new operating system.
Obviously part of this is just arguing over semantics though :)
That is very useful work to squeeze more performance out of existing software, I would say there is still a lot more to be gained from big wins in more efficiently distributing computing power like cloud computing and containerization (which are the kind of non-obvious ideas that require systems research to happen before implementation).
I'm not a systems researcher on the verge of becoming a millionaire so I don't know what those ideas are but anyone can see the untapped potential is enormous.
Obviously part of this is just arguing over semantics though :)