VS Code is not an IDE, it's more like the evolved GUI-Version of Emacs. And it's now 9 years old, so I would think it has established itself well for this decade.
> We also have Sublime Text 2
It's now at version 4, still in development. But being a commercial app, which is also not that cheap, you will naturally see not too many people using it. But considering they are still developing it, they seem to still make money from it, so enough people are using it I guess.
> Once in a while (in the last 15 years) I see the odd vi or vim user. They continue to exist like me with emacs.
That's a very strange observation. There are significant more (neo)vim-users than emacs-users around. They are probably the second biggest crowd in text-editor-space, only beaten by VS Code at the moment. It's far more likely for emacs to die, than for vim.
> Point is - emacs will be around for many years to come.
That's true for all of them. As long as someone maintains them, people will use them. Software will only die when they don't start anymore or the users left them. And at the moment Emacs seems more at the position where users will slowly die of old age, than Emacs not starting anymore. So another 30, 40 years, and Emacs might have a real problem.