Why rewrite if thing exists?

You can use those expensive engineers to build more stuff, not rewrite old stuff

For some people the relevant properties of "thing" include not needing overpowered hardware to run it comfortably. So "thing" does not just "exist", at least not in the form of electron.

Cause it's (allegedly) cheap and you can do much better? Avoiding rewriting things should become a thing of the past if these tools work as advertised.

Why did they create Claude if ChatGPT already existed?

suppose, for them generating code is indeed free (tokens), but autonomous coding is not solved (at least yet)

if it gets solved, (1) we are all f....d! Not only software engineers. (2) they can rewrite it using Assembly. they == AGI

Because these tools are good at using frameworks with a lot of examples out there.