Wow. For an MMO that is quite impressive. Very interested, keeping an eye on this. Is this using UE5?
It's on Unreal Engine, but otherwise they don't specify. I would assume so, since there are relatively few reasons at this point to not upgrade a project from UE4 to UE5.
BTW, we should be aware that NCsoft has a lot of its own technologies and systems, so not that you did this, but we should be careful to not point at a trailer and say, "Wow, look at the power of UE5!!" because there's of course more to the story than that. (We still haven't had a full AAA game released on UE5, so we don't know it yet, but there will be bad-looking and average-lookin UE5 games....)
Although this game is Korean, the point stays. The reason is simple: Making a game look fantastic with modern tools like UE is easy. You just keep adding stuff. The hard part is making so it doesn't run like ass.
So, kind of? Making a game look fantastic in UE still isn't "easy" (although kitbashers can make something incredibly pretty by getting the right assets off of Marketplace and casting Lumen all over it...), and this Project LLL isn't just some off-the-shelf demo of familiar assets / animation / effects. You're right that UE helps a lot, but I would say the reason Chinese and Korean studios are coming out with fantastic-looking training is that they have a whole industry who have been training and raising students for years in the background as technical support studios for big games and CGI films. Now, that talent pool (plus some changes in the economy and international game consumer base) has tipped over into making homegrown products for international release. (It's not so recent for Korea, but there's similar reasons for the boom.) They've got people who are really, really, really good at UE design and high-resolution asset creation there... whether they can find the same skill level in producers and directors who must lead a complete game to release, that's a different matter (the running joke is that there's a cool-looking "Project #" for every letter in the alphabet, but few of these projects have released as real games,) but both territories are on their way to making their presence felt in gaming.