I think spec-wise the Air is good enough for almost everyone who isn't doing video production or running local LLMs, I just wish it had the much nicer screen that the Pro has. But I suppose they have to segregate the product lines somehow.
It's not just the weight - Air is also fanless (and still runs cold).
And yes, with enough RAM, it is a surprisingly good dev laptop.
Really too bad you cannot upgrade to 32GB RAM though =(