Drupal can be a real PITA to properly set up with caching. If you're running anything above 10 req/s your server is going to melt without. Oh, and it's always worth a try to swap the default search for Elasticsearch, Solr or any other external engine.
That AngularJS is a slow piece of ... is another part. I coded up a simple Twitter client using Cordova with Angular, scrapped and rebuilt it in jQuery with Cordova (was a test if one can actually build a backendless Twitter app). Such speed, many awesome.
I guess many of the "hipster" JS devs use the latest, max-spec macbook/iphone only and totally ignore the rest of ordinary PCs/average Android phone, or they wouldn't dare to touch Angular and friends even with a pole.
