Absolutely, though I do have to point out a couple things:
(1) The GG/BG ratio only began to increase in 2022, even though the Fourth Generation started in 2018.
(2) For each month where the GG/BG ratio exceeded 100%, I looked at which girl group albums were mainly driving sales, and they are:
October 2011: SNSD – The Boys
December 2011: SNSD – The Boys
August 2022: IVE – After Like, Twice – Between 1&2
September 2022: Blackpink – Born Pink
March 2023: Twice – Ready to Be, Nmixx – Expérgo
May 2023: Aespa – My World, Le Sserafim – Unforgiven, (G)I-dle – I Feel
January 2024: (G)I-dle – 2, Nmixx – Fe3O4: Break, Itzy – Born to Be
February 2024: Twice – With You-th, Le Sserafim – Easy
Thus, it's not just Fourth Generation girl groups contributing significantly to sales.
This makes me think that it's not simply a matter of generation, and that there must be other factors at play.