Just as with anything it's evaluated on a case-by-case basis. Serverless is GREAT at starting something, testing it and then evaluating if it's even worth spending time to work on actual server-based stuff. You can get stuff going immediately with little effort without the overhead of setting up a box, managing deps and all the nuances that come up standing up classic servers (even in the cloud). Is it a silver bullet? No, though I'd say it might be for fleshing out ideas.