Not using either of those things sounds like a benefit.
Re:My Current HTML Boilerplate
by Mauricebranagh on Tuesday April 27, 2021 @08:04AM
(#26954785)
Yeh want to justify your ROI you will :-)
And using GTM instead of hand coding every thing is a win
W3C HTML5 validator will issue a single warning for not having an openning html tag with the lang attribute. Other than that there are no errors. It is not breaking any standards. As sibling commented I would just add the html tag with the lang attribute.
I don't use GTM or GA or almost any JavaScript whatsoever.
No standards are broken here. Maybe you can bother to read them:
https://html.spec.whatwg.org/#optional-tags
There will also be no issue including GTM/GA or other scripts.
Just blatantly breaking standards like this is not a good idea seen some real howlers from sprint back when I worked on x.400.