Apps must run on specific platforms for specific devices. The app space, while large, isn’t universal.
Websites can be viewed by anyone with a web browser.
And that doesn’t mean foregoing modern features:
A web browser must only understand HTML. Further, newer HTML (like HTML 5) is still supported because the browser is built to ignore HTML it doesn’t understand. As a result, my site can run on the oldest browsers all the way to the newest ones. Got Lynx? No problem. You’ll still be able to find matches nearby. Got the latest smartphone and plentiful data? It’ll work there, too, and take advantage of its features.
This is why progressive enhancement is so powerful.
My site will take advantage of newer technologies like geolocation and local storage. However, the service will not be dependent on them.