I hear you. I don't understand the reasoning behind frameworks propensity to abbreviate things, especially at "atomic"/utility levels. I think it partially stems from wanting to prevent ignorant knee-jerk reactions like "hurr durr why not just write inline styles".
I wish framework devs would just hyphenate (or even colon-ize) the CSS property names fully like "display-flex justify-content-start". I think Bootstrap does their own pattern like "d-flex", but all that does is require one to visit the docs to view some less common properties. Autocompletion pretty much makes typing these a breeze, and having less opinionated patterns for property names will make it less painful transitioning between frameworks.