Comment by jimbokun

The web did have HTML and CSS, but as the author notes those have been bypassed for Web Assembly and other technologies.

Date picker and credit card entry should always always always use the default HTML controls and the browser and OS should provide the appropriate widget for every single web page. For credit cards especially the Safari implementation could tie in to the iOS Apple Wallet or Apply Pay and Android could provide the Google equivalent. This allows the platform to enforce both security policy and convenience without every developer in the world trying to get those exactly right in a non-standard way.