Blablabla.
How about making some substance instead of magical thinking?
-UberShader nerver changed since it's creation (outside correcting few MDL bricks behavior).
-PBRSkin is a bastardized version of UberShader with a slight change for artists's workflow (bump maps->micro details, probably inspired from real time engine)
That's it. Absolutely nothing of importance changed in nearly 10 years. Making color maps twice the size is not progress and bring very diminish return because how translucency is used (blur details at the surface, also why jpeg is used over png/tiff). But it looks like Daz3D has a bridge to sell you.
G9 looks better because people are getting better at baking maps for a more than 10 years old shader. There is also way more accessible tools and ressources all over the web. You would have seen the same progress with or without G9. People will fall for marketing but it's none of my business.
The best advice you can give for new developer using Daz studio is not to buy the lastest Daz skin, but to be more familiar with how they are made and how the shader is used.
Just for shit and giggles, this is a Victoria4 skin from nearly 15 years ago, before UberShader was introduced:
View attachment 4000559
G3/G8/G8.1/G9 doesn't matter outside those points:
-UV mapping
-Model rigging
-Asset compatibility
UberShader/PRBSkin doesn't matter outside those points:
-Micro details for PBRSkin (you still can use fully baked bump)
-More options for UberShader (transmission color mode, top coat layering, gloss, cutout/alpha, I may miss some)
End of story.