I'm really surprised how the Gamecube was able to run circles around the PS2, despite being cheaper and using just a standard CPU/GPU combo.

I think with the Emotion Engine (PS2) and Cell (PS3) Sony got a bit obsessed with things like vector coprocessors that are theoretically very powerful, but basically require a programmer to meditate under a waterfall for 5 years to actually master. I don't think they had a reputation for providing the best support libraries etc. either.

Of course Xbox and Gamecube also released at least a year later than the PS2, and graphics tech was moving fast at the time, so that was an advantage for them as well.

I think the GameCube would have been much more of a success had Nintendo not opted to go with 1.8GB mini DVDs in an era where huge open world blockbuster games were filling up 9GB dual-layer DVDs on other consoles.

Extra silly when you consider that the N64 had already been hamstrung by the decision to use <= 64MB cartridges over CDs.

Historically it's in-line with Nintendo's policies around guiding content however.

After the CD-I debacle, Nintendo was not at all on-board with the idea of disc-based storage. One of those reasons was loading times.

Another was likely that they had concerns about games that were more 'FMV' than game; This really -was- a legit problem in the 90s. By keeping things constrained, it limits the temptation for a publisher to push out a crappy title filled with cutscenes.

It wasn't though. The cube had a few extras built in, particularly in texturing (compression and a texture register combiner), but in terms of flexibility and straight line speed the ps2 is definitely ahead. Burnout 3 and revenge, for example, were not possible on gamecube at the same level of performance. Gamecube has no vertex shader equivalent and has less than 1/2 the SIMD throughput per clock.