I hear this a lot but I've never been able to get concrete examples. I don't notice any inconsistency with my system or any of its applications, I don't have issues with misaligned icons although I'm not sure where we are even talking about there's a lot of places that icons exist. But on the task bar notification tray and within the file browser I don't notice any misaligned icons anywhere.

I suppose I can't speak for the entire fleet of KDE software as to be perfectly honest I don't use much of it, that's kind of the joy of linux is you aren't locked into a particular ecosystem and I have found that the only KDE applications I really make use of is dolphin, Kate, Krita, and kcalc. Outside of that i have things like mpv for video, clementine for music, etc. Hell i use gnome disks for making bootable flashdrives i really like it easy just apply an image click go sure I could do it with DD in the terminal and sometimes I do but it's nice to be able to just right click context menu an ISO and write it to the flash drive.

I don't really see the need for all my applications to be unified under a very specific theme or design philosophy in fact I generally prefer that they don't. It often creates applications that have limitations or other problems for the sake of maintaining the design philosophy. I want a program that does a thing and does it very well regardless of how it may lay that out. but I suppose for some people a cohesion between different tasks is important and thats fine too, i just don't really understand it for myself