1. Browser APIs have subtle differences, or don't always exist in every browser you need to support (e.g, https://caniuse.com/)
2. You'll need at least a transpiler (if writing anything above ES5) and polyfills to solve #1, and if you're diving that far into the JavaScript tooling chain (bundler + babel), might as well choose to use a framework.
2. You'll need at least a transpiler (if writing anything above ES5) and polyfills to solve #1, and if you're diving that far into the JavaScript tooling chain (bundler + babel), might as well choose to use a framework.