I'm sick of hearing this bullshit.
Nobody is using those programs solely. If you're running excel you've also Chrome with some web sites opened, also running Spotify or Slack or whatever in the background. Then add Windows running who knows whatever dozens of services constantly. Even an empty Chrome instance starts with a 6+ processes. If I open a handful of tabs the I can easily observe the CPU usage graph making full use of all cores even if momentarily. And these are very basic baseline usage scenarios that's applicable to every single computer user.
I'm sorry but I can't help but think anybody still parroting this bullshit claim in this day and age either
1. doesn't know shit about computing
2. is a narrow minded gamer who thinks only metric of performance is FPS
3. is a fanboy apologizing product segmentation via low core products (beware these fans exist both on intel&amd sides)