This is true, to get stronger you need resistance. The trick seems very much to be knowing what is worth it, and what is not. How to stop fighting yourself on everything and instead put that energy towards how to either work with, around, or against the outside influences that keep you from living in alignment with your wants and needs.
At least for myself I often find I’m so angry and emotional at other people in my life, their habits etc, that when it comes to fix the problem I have 0 energy left. It’s also accepting that there often is no fixing the problem if it stems from other people being idiots, lazy, or toxic. Many people are just not anyone you should be wasting time or energy on if you 100% don’t need them for something important in your life.