> Well, instead of repeating inline class names everywhere, you end up with CSS properties repeated everywhere. Not really seeing the difference.

It’s like the difference between

  app_name = "Foobar"
  print(f"Welcome to {app_name}")
  print(f"Learn how to use {app_name}")

and

  print(f"Welcome to Foobar")
  print(f"Learn how to use Foobar")

Any good programmer knows why the former is better.