It is an interesting decision point, and I get your reasoning. But, I have noticed there are a good number of websites that could be better for their users (especially mobile users), because someone just took the defaults.

Not high priority, but if Caddy would offer a report of things that aren't configured but perhaps should be...that could help. Things like Cache-control/Expires/Etag headers, Gzip/Deflate, Caching, and so on.