So many different purposes. Sometimes control is necessary for everyone's benefit - government has a legitimate claim to power. Sometimes control is self-interested - it does one party more good than it can do the other. Sometimes control is about a brace for an uncertain future - the American Empire right now is being seriously challenged for its global primacy. Sometimes control is about self-benefit - it consolidates power specifically to disadvantage the other power. Etc. Etc.

Power consolidation right now is a mixed bag. Those who want power for their own purposes find a good partner with those who consolidate power for noble purposes find a good partner with those who brace for the future, etc.

You can only pick voices from the cacophony if you train your ear in one direction. They are all there and it takes every singer in the chorus to work.

Suppression of dissent primarily, which is why the internet is and will increasingly be under legislative attack. It has served as one of the last bastions of anarchistic freedom of thought, which threatens the powers that be.

Said suppression only happens when you can reliably tie identities online to identities offline. Hence parallel construction, etc.

for its own sake. for the thrill of being the top-dog, for the giggle of a nation of minions scared shitless into begging you to take more power so you can scare them more.