In your example, `.m-0` and `style="margin: 0"` aren't equivalent in this paradigm (even though they happen too be technically equivalent). `.m-0` really just means "no margin". If you look further down the article, you'll see:
.m-1 { margin: 0.25 rem; }
.m-2 { margin: 0.5 rem; }
/* ... */
.m-10 { margin: 2.5 rem; }
As you can see, the numbers don't match their values, the class names are meant to be relative to one other.A better way is to use constraint-based design and come up with a system where you would only have `.m-none`, `.m-xs`, `.m-sm`, `m-md`, `.m-lg`, `.m-xl` (for example).
Libraries like Tailwind give you WAY more than you're going to need and you should only really be using a subset.