> I always wonder how many words have an etymology which predates written use significantly due to the "class" of people who use that word
I studied a bit of Shakespeare at university, and my awesome lecturer (https://researchers.uq.edu.au/researcher/619) was always very clear to note that for many phrases "Shakespeare was the first to write it down", which is quite different to "Shakespeare made up this phrase / word".
To your point, he of course was attempting to write for a variety of classes, including the illiterate (his plays weren't written to be published, that only happened after his death - they were ephemera to be performed and witnessed). His success may very well have come from using many phrases that the "lower class" would have recognised from use not just inference.
I studied a bit of Shakespeare at university, and my awesome lecturer (https://researchers.uq.edu.au/researcher/619) was always very clear to note that for many phrases "Shakespeare was the first to write it down", which is quite different to "Shakespeare made up this phrase / word".
To your point, he of course was attempting to write for a variety of classes, including the illiterate (his plays weren't written to be published, that only happened after his death - they were ephemera to be performed and witnessed). His success may very well have come from using many phrases that the "lower class" would have recognised from use not just inference.