It reduces the JavaScript sent to each page even further because it doesn't have a runtime per se. Basically each component is "compiled" to a set of imperative DOM instructions with some helper functions.
It's not perfect but I'm willing to accept all its shortcomings because of everything I get in return.
Sometimes I hit a little bump on the road which would be faster/easier to solve in React/Vue/etc but even including those slowdowns I save so much net dev time it's crazy.
Hopefully they will get there one day but so far it gives me the feeling that I could hit a dead-end with it at any time.