Shopify had a problem where JavaScript import maps would break if any modules loaded before the import map, and you could only have one import map per page - which made them basically impossible to use in real websites where different developers contribute code.

So they worked with browser makers to fix the web platform itself by creating a "merge algorithm" that lets you have multiple import maps and load modules in any order, automatically dropping conflicting rules to keep everything working.

Now import maps are actually usable instead of being super fragile, and Shopify can use them for better caching performance without everything breaking when theme developers also want to use them.