Surely at some point it becomes easier to just switch to UE4 than keep bolting new techniques and features onto UE3. That said, it is impressive how much they were able to squeeze out of the engine given its age. I actually find it rather interesting from an academic POV, seeing how far old tech can be pushed; Splinter Cell Blacklist for example came out in 2013 using Unreal Engine 2.

The graphics themselves look very good, however half the framerate, while understandable, is pretty significant.

False.

False.

Indeed.

Video isn't representative of what you will get in the real world, there is compression and all that.

Not everyone games on an archaic 720P display.

Larger, higher resolution displays will make smaller details more pronounced.

Comparable? No. For simpler, 60fps games? Most certainly.
The fact it is not 60fps will have some caveats on gameplay, whether that is something that is valuable is entirely up to the individual though.

Personally, I can't stand 30fps, but you really don't have much choice on console, you get what you are given.

I think it depends on the game, as well as of course on the individual. Games like Splatoon 1/2, F-Zero GX, etc, I'd never want to play at 30fps, but Outlast I don't think I'd mind so much as it's slower paced.

At some point, sure.  But it also depends on what you are looking to do with the engine.  And the scope of your project.  If your project is already highly ambitious and will already take a long time and a lot of money but on a technical level you aren't looking to do anything the current engine can't do with a little help, it's hard to justify the jump to a new engine.  Or if your project isn't that huge but your team and budget are fairly small and your technical abilities with the engine are strong enougn, same thing.  Switching engines can be a real headache and slow down development considerably.  

If results like this can be achieved on a last gen engine, in a game not built for the Switch's hardware, which was ported in a matter of weeks, it bodes well for what the system can pull off when talented developers give it their all.

Indeed.  Seeing how Wolfenstein 2 looks makes me want to see a partnership between id and Nintendo for an exclusive new IP using id Tech 6 but built from the ground up for the Switch for the best results.  I think it would be pretty incredible.  Never gonna happen but still, would be cool :P

That would be pretty rad. I think it's going to be fascinating to track Switch's graphical progress over the course of it’s lifespan; in its first year or so we already have games like Outlast II, FAST RMX, Mario Odyssey, Kingdom Battle, Doom, and soon Wolfenstein II showing what can be accomplished. As tools improve and developers gain more experience with the hardware, the bar should be raised even further.

Not everyone plays on a full HD or 4K display.

And in fact, the vast majority of people cannot tell the difference between 720p and 1080p (or 30fps to 60fps). And even if one does, that doesn't mean that he / she will actually care. I own a 4K display, and a pretty powerful PC, and can play most games in 4K.

Nevertheless, I'd rather play games like Skyrim on my Switch, rather than the PC.

Oh, I don't agree. The systems have big differences in the graphics technology. But the effect of diminishing returns hits: The higher the graphical level at all, the smaller the noticeable differences. This is different, for a new technology that uses much more processing power and makes some clearly visible differences. If we hop such a technological barrier though is depending on the games and what they use as ideas.