Uh, making the arcade picture use smooth linear filtering while GBA images use nearest pixel filtering is misleading AF.
The image shows how little details the GBA version of MK ultimate has compared to the original version, it lacks both details and colors compared to the original version, yet it looks pretty good for a GBA game.
No amount of filtering will change that - the GBA is not close to be the Pinnacle of 2d gaming in any way shape or form, it never was.
As for the strong library, I assume the argument could be made (you just did) - but as someone who fell pray to the hype back then and bought the Advance Wars bundle with some zelda game, a metroid game, arguably some of the best titles on the machine. Yet the best time I had was with Wario Ware inc. (yes Wario ware, a true portable game). For the rest, as far as I am concerned its 2d games library isn't up to par with the 32-bit machines (neither the PSX, nor the Saturn), or even any of the 16-bit machines (Gensis, SNES - even the TG-16, especially with the CD add-on).
But this is not the question the question is about design;
The GBA was basically SNES2 and the pinnacle of 2D game design - change my mind
That's a lot easier, the GBA is not even as interesting as some machines released back in the 80s, especially if you consider arcade hardware.
There is no reason to think that the GBA was the pinnacle of 2D games design, or even one of the top 2D games system, even the SNES games that were ported to it had to have some cuts in resolution (but they had less slow downs).
None of the games below could be ported to the GBA withoutserious cuts in colors and/or resolution (both essentially means a loss of details).
Be warned there are no Nintendo games in there.
ARCADE TITLES:
1988 - Altered Beast Arcade
1992 - Golden Axe Revenge of Death Adder (arcade)
1989 R-Type 2 (Arcade)
SOME CONSOLE GAMES
2000 Guilty Gear X (DreamCast)
1992 - Thunder Force IV (Sega Genesis)
1993 - Lords of Thunder (TurboDuo)
1994? - Castle Vania: Rondo of blood (Turbo Duo Japan)
Nanatsu Kaze no (Sega Saturn)
Castlevania SOTN (PSX)