I feel you. Vim has been such a staple in my dev life. So much that switching felt like betraying sweet uncle Bram ;-) And without the need to write typescript, I probably wouldn't have switched. But what made me stay even for non-typescript work were the little things, like the positions in the location and quickfix list being auto-updated while editing, being (feeling?) faster and more responsive, the saner default settings (server usage) etc.

Regarding lsp integration, it's just nice to have project-based instead of buffer-based auto-completion, auto-insertion of import statements etc. Definitely makes me more productive. Setting it up the way I wanted (non-obstrusive, on-demand) was a bit of pain though.