Thanks <3

Okay, those were some fairly empty answers you got on your thread.
The primary reason there is no similar site (or function on this site) for giving away non-Steam games is that Steam's API (the interface other sites can connect to Steam with to pull information off it) allows for checking if games are activated on account or not. None of the other platforms offer that, which means none of SG's automated features could apply to such. As such, there's absolutely no security, and a whole ton of a lot more moderation- so it's simply not worth being a function offered.

That said, there are also equitably issues- GOG games are sometimes valued higher and sometimes lower than Steam games, but Origin and especially Uplay are generally valued as lower than their Steam counterparts. That'd completely devalue the CV system, with people intentionally trading Steam games for handfuls of low-valued Uplay games, to up their CV.

Basically, there's a whole lot of underlying reasons (as to why you can't give non-Steam games on SteamGifts) besides simply "it's the rules" and "that's what this site focuses on". :)