That’s the idea, but in practice since the data exists independently on each server, it takes network time and computational time for them to align. In practice I expect comments to function as you expect, and upvotes to be slightly off depending on which instance you’re viewing from.
Things get a bit more weird when an instance gets defederated from another instance. My understanding here is that if you have instance A defederate from instance B, but instance B was listening to some of instance A’s communities, that instance B will have an independent replica of that community that doesn’t sync (this happened when beehaw defederated from open registration instances like lemmy.world).
For people unfamiliar with the vim ecosystem (I assume that’s at least part of the down votes), it’s actually much closer than you’d expect. If you’re only familiar with vi/vim, nvim customizations are essentially on feature parity with vscode, with the added benefit of the vim-first bindings.
What you have to do is install a customized neovim environment. Lunarvim, astrovim, nvchad, etc. Most of them have single line installation options for Linux, and then it comes with a bunch of plugins that will pretty much match whatever you’d find with vscode extensions.