Tons of people often over exaggerate the compression artifacts when the most noticeable loss occurs in high dynamic range with common compression formats ... 

I certainly wouldn't have claimed that the PS2 was a "less" capable hardware compared to GC. "Different" would've been a better term since one offered advantages with higher resolution textures along with hardware bump mapping support when the other was better in everything else such as rendering particles, more detailed polygon mesh and handling AI ... 

Those weren't GCN's only advantages; notably, it also had a significant upper hand in multitexturing, allowing for much more extensive of other surface shaders besides bumpmapping. This is how we got GCN games that threw around tons of textures layers at once; not just bump maps, but gloss maps, specular maps, dirt maps, detail maps...

The very weak CPU of the PS4 was the bottleneck for AC Unity. So no.

The CPU is the weakest link in all three 8th gen consoles. Their clock speed is pretty low, which is far from a death sentence  as there are many other factors in a CPUs ability, but they are still a little on the lightweight side overall, especially compared to modern PC CPUs.

This generation is weak, but I'm not sure twice as much power would have made such a difference. I could be wrong, but I don't see so much difference with PC games I need it. On the contrary, low entry price, early adoption, easier development and standard architecture should make this generation better than a state of the art and hard to program 600$ console.

I didn't know where to ask this, but how/can you post pictures

You can't directly post pictures. You can upload a picture to www.picpar.com for example then link it by clicking the picture icon (in a rich text reply or quote) and copy paste the url in the box that comes up.

The Burnout games on the PS2 featured both gloss maps and specular highlights too. Dirt maps can be baked into the textures so I'm not sure what the advantage is when almost every platform that supports textures can do it too ... 

"Detail maps" is another form of bump mapping ...

I didn't say PS2 couldn't do gloss or specular maps, it can, but its more limited multitexturing ability means it can't employ effects that use this technique as extensively as GCN can.

And detail mapping isn't necessarily bumpmapping; it's another texture scaled differently to make a surface appear more detailed up close.

Sorry, I read that as the "GC can do gloss maps and specular maps compared to the PS2" ... With that being said you wouldn't mind showing or pointing me to some GC games that do these things, right ?