@matigo I quite fail to see the point of any icon setting other than default for the sort of desktop pictures I favour. I never liked dark mode and relying on shape only for the clear or tinted “glass” look (that strips all colour out of the icon images) is bullshit.
Some YouTube reviewers favour the Reduce Transparency setting but that applies a nasty grey aspect to parts of the view. These folk use dark mode. I prefer instead to use Increase Contrast, that puts a border around app sidebars. The increased contrast also makes the Control Centre icons merge less into the background image.