There is no 'harm'. Nothing will break
But at the extreme end of things, every single system made will have a 'bottleneck' of some sort.
Unless every single part, GPU/CPU/RAM/monitor, is running at 100% equally....one of those is the weak sister. The other parts are waiting on that thing to do something.
For instance...an uber system with a EVGA 1080 GPU, i7 CPU, 32GB RAM, and a 12 year old 15" 4:3 monitor...the monitor is the bottleneck in the system.
Change that to 2GB RAM and a 4k monitor...the RAM is the bottleneck.
With all top end June 2016 parts...at some extreme resolution and detail...some 'thing' will max out before the other parts. That thing is the 'bottleneck'.