There's no reason why someone using babel needs to use ES2016+ features, they can stick to ES2015 just like this article.

I'd actually recommend avoiding the still-not-standardized features as you'll have less/no change when it lands in browsers.

I looked at the prospects of starting a React, Aurelia, or VueJS projects a few days ago and a year ago. Anyone who wants to wait to upgrade to these new things will be really happy to see how much nicer these things get every year. Tooling and starter kits just keep getting better, and best of all, you could probably wait a long time to switch and miss out on nothing important.