That was his point. The rails stuff he learned five years ago is all still considered good practice, but the JavaScript stuff he learned (listed above) is now considered antique.
(If he means SASS vs SCSS syntax, I recall using SCSS ~8 years ago, so it's an odd choice to include either way.)
Once you've used grunt, using gulp is not a big logical jump. Then to webpack. Whatever, they're just build scripts! Roll your own shell scripts if you want! A day to learn them, or a lifetime of being a hater.