It is more common these days than it was for websites to support multiple styles/layouts. Whether that's because they're responsive or because they allow you to enable dark mode or because they support rtl layouts. Class names such as text-dark-soft or align-right will be misleading if text-dark-soft ends up closer to white and align-right is left aligned as a website is evolved to support these features.
Not a criticism of this approach; this is easily fixed by using names such as text-emphasized-soft or align-start (for example), just pointing out the examples in this article could be lead to problems
CSS variables can also be used to encourage picking colors or padding/margin from a curated list. The approach in this article is not required to solve that problem