Tech CEOs can easily outlive their usefulness once the machinery is built, and can easily find themselves labeled "terrorists" if they try to fight back with whatever feeble power they have.
Political factions, purges and patronage is what comes next, amd despite their inflated egos, they won't be the patrons.
If you own everything, and you bomb the populace, you bomb your own stuff.
If everybody works for you, and you bomb the populace, you bomb your own serfs.
And those faceless individuals who are actually holding the weapons, and actually know how they work, and actually know, in a detailed, hands-on way, how to do coordinated violence with them? It turns out they're secretly members of the populace. You'd better make sure they think it's in their interest to keep using the weapons the way you want them to.
You can bomb people into oblivion but if you actually want to control them, most of the things that give superiority to a fixed group of rich are useless. Violence is still democratic if you're trying to get anything useful out of the people you seek to control. If you have 5 people and 3 of them are slaves with an AK-47 and a donkey, you have 0 slaves not 5 slaves.
Obviously the rich/powerful can't stay that way in a glass desert with no plebs to do their bidding, at least for now, so most of the technology the government and rich have are useless for subjecting a hostile populace.