This is correct, but the entire structure of modern industrial society is not based on what should be now that more and more people realize its flaws.

"Your sense of worth should not be tied up in your job" only does so much when the average person's reality is that his or her job is the means by which they survive/thrive economically, a primary factor in whether or not they attract a partner and reproduce, etc.

It’s just an excerpt and not applicable to some but Rainer Maria Rilke’s Letters to a Young Poet has a good if longer bit: “Are not all careers the same? Filled with demands and people filled with animosity towards the individual. At the same time absorbing the hatred of those who have silently and sullenly adapted to dull duty.”

It's not like it's what you spend most of your life's hours doing or anything like that.

What I would say, and perhaps what you actually mean, or if not then at least what you might now consider, is you shouldn't give anyone else the right to declare your sense of worth, including an employer.

“I wish I had spent more time on my business” is totally different from “my work gives me a sense of purpose and makes me feel like I’m contributing.”

Without my job I can't afford my mortgage and groceries. It has very little to do with a sense of worth