Did you not see the comparison section though? Rtype 3 was a garish, bugged-out, last-of-its-era shootemup, with weird triangular foreground plates and gnarly color combinations and funky blither effects and huge monsters with great, gross detail but not much room to animate on the limited SNES. (I assume many were moving background tiles?) It was not exactly a "really pretty shoot em up.)
Also, this remake has to fit the "Dimensions" model of being accurate enough to the original that you can swap 3D for old 2D on the fly. Every oddly-placed pillar, every waggly enemy arm, every boring industrial complex, every right-angle laserbeam turn, every weird choice has to be there in the remake for it to be at all faithful to the original. The graphics also must be readable even as they add lighting and surface effects and additional particles to enliven the world, because if the new graphics make it tougher to see what you're doing in these punishing SHMUP stages, they will have lost the playability that makes these games worth playing.
What other games are you thinking which get this job done differently?
Well, for one the shoot em up I'm working on does it differently, hand drawn graphics that are not pixel art (I can do pixel art of course and even though much of the art is more 'air brushed' in style, much of the animation is done by hand sometimes pixel at a time but high resolution (well, 1920 x 1080). But we aren't here to talk about my game other than know you can go a different route than pixel art and 3D. Other games that do it very well are Rayman, Ori, Cup Head (both Rayman and Cup Head actually featured shoot em up sections), admittedly those are more cartoon-ey than the likes of R-Type but hand drawn art can very much be used to make a very nice looking shoot em up.
There is something very 'off' with the 3D in this Dimensions title in my opinion, it looks cheap, R-Type is a great inspiration for me, as is Darius and Gradius so I personally am disappointed with the way this looks.
R-Type Final did better and that's years old, going back further Gradius 5 looked better as does Ikaruga if you really must go the 3D route and pixel art wise I'd argue both R-Type 2 and Leo looked better than this one (although to be fair I havent really seen enough to judge that properly and I am talking about arcade games here, not SNES). But the point is, pixel art back in the day was a necessity, the hardware meant we had to do that, but even then due to the TV's in use (CRT) pixel art didnt look all that 'pixelated', it looks better than it does now. Sure, it does a job for that 'nostalgia' factor, but it isnt really how we remember the games, back then they appeared more detailed due to the limitations of CRT (which blurred things slightly) to our brains filling in the blanks. The thing is, if the game looked like the cover art for that youtube video it would look great
Now I get the arguments about the 'Dimensions' title, but I just see it for what it is, not great 3D even if the 2D pixel art is. One thing I do know though (or at least I hope) is that the game will play well.
Edit: and yes, yes, I know all about background detail making it hard to see enemies and bullets, but there are solutions to that