In regards to dismissing multiplatforms. There is plenty of merit there because there are so many variables in terms of the development process etc. However, over the generations with all the custom hardware, there have always been advantages on both sides of the hardware war, even from the "weaker" console. Custom hardware allows for that, exploiting strengths not available on other consoles.
SNES vs Genesis
Both console showed their strengths in multiplatforms. Typically SNES had better colors/music and Genesis better animation.
N64 vs Playstation
N64 had less pixelated textures, but blurrier.
Ps4 vs xb1
Even with extremely similar hardware, the more powerful ps4 GPU allowed for higher resolutions almost always, however, the xb1's CPU allowed for better fps in limited cases.
360 vs ps3
360 largely shows its advantages with easier development process. However many ps3 multiplatforms were clearly superior due to wrangling the cell and supposed "fast RAM" of the ps3. PS3 was also considered one of the most difficult consoles to code for.
I'm missing examples above, but even Saturn and Dreamcast have also demonstrated their abilities despite being "weaker." 2D games for example on Saturn.
Gamecube vs Xbox
Per this thread, this is where it gets odd. Suddenly, the Gamecube with its custom superhighway of memory compared to supposed bottlenecked Xbox shows almost zero advantages in so many multiplatform variables? Various games; platformers, racers, shooters, sports games, various game engines, physics heavy, open world, GPU heavy etc etc. In almost every single case, we're forced to believe that all developers were lazy over the course of 4-5 years?
But yet in the past generations, even weaker hardware with custom advantages showed their strengths in multiplatforms.
Not only that, we see Xbox multiplatforms that are possibly the largest gap between two rivals, ever, especially considering their close release window. On top of all that, the most demanding games of the generation weren't even attempted on Gamecube. Half-Life 2, Doom, Riddick, games that crippled high-end Hardware. Developers also expressed on more than one occasion that the Xbox was the only system capable of running their games.