I used to be of the "and things on the web should all support http unless they really need https" crowd but corporations (ISPs, hotels, airports) driven by the ad sales industry really drove me to the "nah, we should really get everything on https" crowd.
<meta charset="utf-8"> means not assuming the default encoding of the client at all, not that ASCII would be invalid given the site's content.
Edit: Forgot <meta name="viewport" content="width=device-width, initial-scale=1">, you probably want this even without CSS. What the client ought to do and what the client does do are different stories and neither are guaranteed to be what you want in the end anyways.
> I used to be of the "and things on the web should all support http unless they really need https" crowd
Supporting unencrypted connections does not imply that the client is required to use them.
> What the client ought to do and what the client does do are different stories and neither are guaranteed to be what you want in the end anyways.
Yes, which is why the reader should configure how they intend it to be and the document author should not prevent it from working how the reader intended.
Supporting both is part of the problem unfortunately.
In principle I agree on how the user agent should behave, in practice leaving viewport as default doesn't necessarily match what the user wants or what the developer wants. E.g. user zoom settings are still applied after the viewport scale setting, just now in a consistent way across mobile devices.
<meta charset="utf-8"> means not assuming the default encoding of the client at all, not that ASCII would be invalid given the site's content.
Edit: Forgot <meta name="viewport" content="width=device-width, initial-scale=1">, you probably want this even without CSS. What the client ought to do and what the client does do are different stories and neither are guaranteed to be what you want in the end anyways.