His existence never erases Anakin balancing the force. He creates Snoke and turns Ben into Kylo Ren. That creates the new imbalance that results in Rey being a new Chosen One.
If Palpatine created/manipulated the people who broke the balance, then that means his survival did nullify the balance that Anakin was supposed to bring. If he’s alive, even barely alive, then the Sith still exist and nothing about the imbalance has changed.
That is how you look at it. That is not how I look at it.
I also prefer to stick to just the movies and TV series in which there is no explanation for how Palpatine is back. In that, I feel that the Sith technicians are trying to create a clone that can hold Palpatne and that Grogu’s DNA is vital to the success of that project and even with that, they cannot create an independently viable clone. Though the do create Snoke. So in my view it is years before Palpatine can occupy a suitable body to have any power. So there is a good period where the force is balanced and peace has a chance to take hold.
“It is possible he was concieved by the midichlorians.”
“You refer to the prophesy of the one who will bring balance to the Force for a little while…kinda…”
Everything is for a little while. Many things have to be done again. And I think that whatever the prophesy, Anakin kind of botched it by turning to the Dark Side, so his redemption and brining balance may not have been as complete, but Rey couldn’t have done what she did without what he had done.