This is (depending on how extreme you are, I suppose) wise. Once you're making more than a subsistence income, one of the keys to long-term financial stability and security is to live well below your means[1].

Doing that also gives you freedom in the sense that you are no longer "trapped" in whatever job you have, because you can develop a long enough runway that you can leave a job before you've found a replacement.

[1] In my youth, I dated the daughter of one of the richest people in my city. I asked him what the key to getting rich is, and his response was "spend less than you earn". At the time, I thought it was a way to to avoid answering my question, but in the decades since I've realized that was actually the correct answer and everything else is just expanding on that.