> To be honest, I still haven't really used LSP much, and most of my experience using similar features in other products (Intellisense in Visual Studio, whatever the equivalent broken thing in Xcode is called) is that it really was never that useful

It's useful especially when you're switching many languages, or working with new libraries.

Syntax error is immediately highlighted. Saves a context switch of changing to compiler tab and back to editor.

With every symbol, you can view documentation by hovering. When autocompleting also, a small window/popup shows docs for currently selected symbol.

You have automated refactoring available in-place, especially renaming. In most LSP it renames across all files and modules.

Granted it's not that useful if you're in-and-out familiar with the stack you're working on. But once in a while you still need to switch languages and use new libraries it will be useful.

I can't go back to pre-LSP world.