Those trenches aren’t in the middle of nowhere. They’re dug around cities and other strategic targets. The fights in the middle of nowhere are fought by mobile combat units.
Besides, these are wars of attrition where killing off the young men who fight wars is the entire point. A robot that takes a few months to manufacture instead of 18 years to raise changes the calculus entirely.
This whole thread is fun to think about, but misses something.
War is largely about fear / intimidation. Yes, an RTS-like "destroy the assets" is how it's abstracted, but ultimately it's about intimidating a leader and population into submission. Keeping the attackers away from cities is very much part of that calculus, as is dropping long-range attacks on those cities.
If both sides have robots that take months to manufacture, the goal would still be the same: "Keep their robots away" and visa-versa "Get into their population centers and seize power symbols". At this stage, with established defenders, the goal seems to be "seize ground yard by yard"
And "outproduce them" aka "grind down their will" is still going to be a viable strategy.
In some sense, a robot fighting force will be a sort of Next Generation Neutron Bomb (TM). It will have the capability to enter the population center of a non-peer opponent and sever communications and secure key locations for immediate occupation by friendly force hoominz - but entirely without the muss & fuss of kinetic destruction or the toll in souls of massed gunfire.
Of course this kind of scenario was the fantasy outcome of the lightning win over and occupation of Iraq, with "thunder runs" and such, but in the longer term it didn't work out that way.
To be fair, the Racism / Xenophobia component is always alive. AFD does exist in Germany, and Trump can get away with saying 'poisoning the blood' (He later said he didn't copy it from Hitler but he didn't apologize)
As I understand it, Racism was a strong motivator in the propaganda. It was part of Hitler's narrative even before he was in power (something something culture destroyers something something parasites lorem ipsum)
Only recently have I noticed that some groups support a Theory that downplays racism because people are obediently blind. I have seen racism and xenophobia and know it is neither obedience nor blind. But as to the extend of the power it held in the Germany of 1930, I have only read about it.
I think it's far more complicated than "racism / xenophobia".
Hitler had delusions about "Aryan" race, white blond people, even though he was not blond. Also, the war was mostly fought in Europe (or at least started in), i.e. mostly among people of the same race.
It couldn't have been "xenophobia" either, given he wasn't even German!
A lot of people who were sent to the concentration camps, besides Jews, were Roma (Gypsies), gays [1], Slavic people, probably more.
I havne't studied history that deeply, maybe this talk about "undesirables" was all just propaganda, conveniently constructed to help fulfill military goals, but it's clearly far from neatly fitting "racism / xenophobia".
Besides, these are wars of attrition where killing off the young men who fight wars is the entire point. A robot that takes a few months to manufacture instead of 18 years to raise changes the calculus entirely.