>>49627457
that's just AD&D
finding laser guns and lightsabers and such from prior civilizations or just straight up "aliens crash landed in our medieval-era fantasy setting" is a classic. it wasn't exactly ubiquitous, but it was always there in a decent measure. outside of the TTRPG space there's loads of pulp fantasy writing that plays with the ideas, cartoons like he-man, etc. everyone loved that shit
though you could say it's fallen on the wayside and only japan still does it on the regular, and I wouldn't say you're wrong. besides some semirecent TTRPG products I can't think of anything the west has done recently that injected futuristic sci-fi into fantasy
is it kinda goofy? yeah. but I love it