Full-time workers: are you able to fill an entire 8 hour day with work most of the time?

I’m interested to hear from people who work office or “white collar” jobs especially. I just got my first full-time job (I don’t want to go into too much detail about where I work, but it is mostly a desk job, though I also work with the public). I’ve been adding more tasks to what I do since being hired, but I still find myself with a few hours on certain days without much to do. I’ve been hearing about a TikTok trend where high-paid tech workers show how they basically do very little work during the day (maybe part of why demand for work-from-home has been so high) and it got me wondering about how common this is.