I change clothes all the time too, still match the pieces of clothing each time.
There's aesthetic value to coherence. There's also design, usability value. I have Telegram, Steam and Firefox opened right now and each one of them displays different minimize/maximize/close buttons on the top right. That's not ideal.
Unfortunately nowadays even the built-in apps on the major desktop OSes are inconsistent, so the temptation for third-party apps not to care is somewhat understandable.