Here's some of the latest filters I use in the uBlock Origin dashboard.
gog.com##.howlongtobeat-section
gog.com##.gog-pp-banner__inner
gog.com##.download-galaxy--variant-2 download-galaxy--variant-5 __text_mode_custom_bg__
gog.com##.download-galaxy-bg-right __text_mode_custom_bg__
gog.com##.download-galaxy__text-container
Those last three entries (maybe four), hide most of the recently added fluff on the success page after purchasing a game.
So all you see is the games you just purchased, and a button to grab Galaxy. Basically it is now similar for me to how it used to be before they went overboard pushing Game Preservation stuff, while neglecting to promote Offline Installers.
I certainly don't agree that download & install through Galaxy is the best way to get your GOG games. Especially as that is almost contradictory to Game Preservation.