That RTX on and off example in the OP is kind of pissing me off as in my opinion it's a misleading piece of material. What's actually happened there is RTX off is without Global Illumination and RTX on is with GI. Yes I understand that RTX is being used to compute the GI in that scene but that's not what the image implies, instead it implies that you cannot have GI without RTX when on the contrary we've seen real time GI (of some form) being done without ray tracing in recent years, as such it should be that without RTX you cannot have as accurate GI as you have when you are using RTX.
Ofcourse then they run into the issue of not being able to clearly show substantial visible difference between non RTX GI and GI that's done using RTX, but atleast it'd be an accurate representation.
I think it's a misunderstanding, you can absolutely have GI without RTX, but the effects of RTX have a more drastic appearance when RTX is computing GI. It's a presentation that's specifically highlighting the qualities and abilities of Raytracing, so they purposely showcase RTX computed GI rather than showing standalone GI.