You still need people to occupy the place, take control of objectives, interact with the population, etc... Otherwise, you are just making craters.
An advanced army with appropriate support can make a soldier 10x more effective, but you still need a soldier to begin with.
As a thought exercise, imagine if ukraine had 100k missiles ready in a silo.
Try the US/Iran war for size then.
I'm not sure what you mean by "completely disable their opponents" - there may not be a country on earth with enough munitions to do this against a competent and resilient adversary - the Vietnam war comes to mind where the US still lost after dropping triple the bombs (by tonnage) of what the entire allied forces dropped during WWII across all theaters
At least that was the case before Ukraine started blowing up Russian factories. And for the rest of Europe, their capacities are somehow even worse.
And in any case, Russian missiles were a drop in the bucket compared to drones.
So building high performance missiles in a volume needed for sustained conflict is not something any military has managed to do so far.
(Not shilling for any side, just my honest opinion, plz dont dogpile on this, I don't care about any side's national greatness)
Imagine if they had air superiority. For some reason people ignore this when analyzing the war in Ukraine. Drones are great for denial (defense). So far they are shit at assaults (offense). Also, drones don't do well in environments with military aircraft. We just don't see that in Ukraine because they are very few aircraft in the skies. The Russians haven't flown into Ukrainian airspace in over 3 years now. They launch their missiles and glide bombs from their side of the border.
The robots are made to kill people on the other side until you hopefully win, otherwise political disagreements could be settled via best of 3 CoD games - or chess if you're more traditional. Recruitment of humans is still required for fodder.