Progressive Enhancement
The topic page on the Remix docs:
Performance: While it's easy to think that only 5% of your users have slow connections, the reality is that 100% of your users have slow connections 5% of the time.
Resilience: Everybody has JavaScript disabled until it's loaded.
How Remix works:
Remix embraces progressive enhancement by building its abstraction on top of HTML. This means that you can build your app in a way that works without JavaScript, and then layer on JavaScript to enhance the experience.
What it means for you (and your users):
It's not about building it two different ways–once for JavaScript and once without–it's about building it in iterations. Start with the simplest version of the feature and ship it; then iterate to an enhanced user experience.