Do dogs hate being alone all day? Do they get bored? Or do they not care?

Before Covid, my dog was basically alone all day while I was at work.

I WFH most days now and it’s not like anything really probably changes with his schedule regardless. He still wakes up, eats, goes outside, then sleeps most of the day during my work day.

But I now feel bad when I do have to go into the office and leave him alone! Does he hate it? Or does it not matter to him and I’m just stressing about it for no reason?