What was the motivation to create this class, given the availability of the native EventTarget constructor and existing shims?

😬 no. I don't know why I thought it was only an interface (i think this belief was based on the comments in https://observablehq.com/@mbostock/synchronized-views). Thanks A LOT for pointing me to the constructor! So: you're right, it's now totally pointless (at least the exercise helped me to understand the internals).

I just remove the dependency from 5-6 notebooks, and it works exactly the same. Thanks for simplifying my life :)

Sorry for putting you through this! 😅 Note that you may still need a shim (like https://github.com/mysticatea/event-target-shim) if you want to support Safari 13 or below both on iOS and macOS. Safari 14 was released in September 2020. EventTarget constructor support: https://caniuse.com/mdn-api_eventtarget_eventtarget

OK, thanks for the complement. I think I will just use the native constructor, as it's for prototypes here.