For the 20% of the things you use 80% of the time (basic completion, goto definition, syntax highlighting), I'd say advanced LSP servers like rust-analyzer are

For the 20% of the things you use 80% of the time (basic completion, goto definition, syntax highlighting), I'd say advanced LSP servers like rust-analyzer are pretty close to what IntelliJ provides. But the heavy tail of 80% of the features which are used relatively rarely is very heavy. The biggest one there is the "change signature" refactor. LSP today can't really express that.