From a quick look it seems like a command you use to reconfigure nginx? And that's separate from auto-renewing the cert, right?

Maybe not hard, but Caddy seems like even less to think about.

I guess I should compare to this new Nginx feature rather than Caddy. It seems like the benefit of this feature is that you don't have a tool to run, you have a config to put into place. So it's easier to deploy again if you move servers, and you don't have to think about making sure certbot is doing renewals.