The Wikipedia page for the HRE states " The empire never achieved the extent of political unification as was formed to the west in France, evolving instead into a decentralized, limited elective monarchy."
Why exactly did this happen? If the HRE originated from the split of the Frankish Empire why did it become a disunited mess while France would become a more united Kingdom. Were there attempts to centralize or unify the HRE and why weren't these able to work?
Well, this exact question is one of the bigger ones hanging over the Holy Roman Empire. I commend to your attention the appropriate section of the FAQ; if it doesn't take you immediately to the HRE section, just scroll to the bottom. As always, more can always be said, so if anyone passing by would like to take a crack at the HRE and its system, don't let this post stop you!