For me personally, being bored at work actually leaves me more tired at home afterwards. I'm working on something so boring at work now and I can't handle it. It's just going to kill me very slowly over the course of the next month.
Now for your second point, I completely agree--I don't want to feel like my job is my worth or joy in life, and it isn't. But at the same time, I wouldn't take a job at an assembly line even if it paid $1M a year.
That's why you work on your side projects at work. I plan and design and write in a text editor my personal stuff all the time. It's just a text editor so it doesn't look suspect.
Now for your second point, I completely agree--I don't want to feel like my job is my worth or joy in life, and it isn't. But at the same time, I wouldn't take a job at an assembly line even if it paid $1M a year.