When and how did drinking chocolate fall out of fashion?

I can resoundingly answer, Yes! I don’t know about individual packets, but definitely tins.

Here’s “Old World Hot Chocolate” shavings.

Yes, they do. I have four cans in my pantry right now. (Stocking up while it was on sale. I use it in my holiday Rum Balls.)

Sorry to be so long in answering. I’ve been out of town for a couple of days.

Back to the OP: I am almost completely clueless when it comes to culinary history, but my WAG would be that drinking chocolate declined when the even stronger buzz of coffee became widely known.