Killmonger was a colonizer and imperialisst who had the colonizer and imperialist mentality, and created instability in that country andremoved its customs and rituals.
Peep how he didnt say he wanted to free liberated people for their own free will. He said he wanted to unite people under the flag of Wakanda.
That is what colonizers did. If you missed that, then you aren't the black liberation thinker you think you are. (trick statement, you never were that)
He even used the expression: "The sun will never set on the Wakandan Empire."
Brits told lies to justify their imperialism, claiming that it was for the benefit of the conquered (see: "The White Man's Burden"). That bit of dialogue was a huge hint that Killmonger was doing the exact same thing in order to get Wakandans on board with his plan for world domination.
On top of that, he was a psycho who shot his own girlfriend in cold blood and choked an old woman for questioning him. Black people would NOT have wound up benefiting from this guy becoming Earth Emperor.