Nah, buddy, swords aren't heavy. A longsword, for example, is 1-2kg typically. My katana, which is a Japanese longsword, weighs just under a kilogram, without the scabbard. You are a sturdy, adult man. Aren't you ashamed of calling that heavy?
You can't what..? Dude, why would anyone wear armor if it didn't allow them to move? You think battles are fought sitting on a bench or something?
Looks like the author did zero research before writing this story, and didn't think twice about the dialogue either. This isn't even isekai, just a VR game series, so the author can't use the "all isekai are trash, so what did you expect?" excuse.