When I say/hear "do svidanya", I usually don't consciously interpret it as "till next meeting" each time, it's a set phrase and it's usually perceived as a whole, "goodbye". Only you if you put some effort to pay attention to the actual roots that you realize, oh that actually means "till next meeting" (especially since in modern Russian, "svidanye", when used alone, now means "romantic date"). Same with "hello" which literally means "be healthy", it registers as just "hello" in my brain, I don't immediately think "they're wishing me good health". But maybe it's just me.

>except, of course, when it does.

To a good first approximation, zero people mean "god be with you" when they say "goodbye". That might be the etymological origin of the word, but meanings shift over time.

Most people don't become polyglots either, though, so that's not a good measure of the utility. It's not a question of language-learners learning etymology would be useful to the man on the Chatham bus, it's a question of whether it is useful to language-learners.

Knowing the etymology of, e.g., "goodbye" makes it click faster/not be weird when you learn, e.g, that "hello" is "Dia is Muire duit" (God and Mary be with you) in Irish Gaelic.

and putting utility aside almost completely, it’s just pleasing to know things.

> except, you know, the person you're conversing with this very moment, so that's a really bad (local) first approximation!

Well there's that saying about all models are wrong, and some are just more useful than others.

My country is thankfully becoming more secular as demographics change, so hopefully that first approximation improves over time.

because forgetting things about the only tool we have for communication, imperfect though it is, is always an improvement. How else will we rediscover them badly?