[Alphasite_]

If it loads quickly, why not? My connection is a sub 3ms ping to the nearby datacenters, what exactly is the bottleneck?

It's not to say there isn't a place for SPAs but I would argue many of these would be better suited to being full fledged desktop apps instead (better performance and snative integration).

[Benjamin_Dobell]

Okay, for you there's no bottleneck, just woeful UI/UX. Seriously, seeing just one stateful element at a time, then pressing "Next". Wow, just wow.

I fully expect that when I type the first few digits of my credit card number that the site knows precisely which card provider I'm supplying and updates the UI (highlight the card type) accordingly and immediately update the security code field to request my 3-digit MasterCard CCV vs. a 4-digit AMEX CID.

To be clear, I'm not suggesting code needs to run on a client. One day when we all have fast enough connections (with minimal latency), including on mobile network, then perhaps all the code can run server-side and we just be streamed the output (video) - which again, updates in real-time!

However, living in the real world as it stands today, client-side scripting is a fantastic solution to a real-world problem i.e. latency and bandwidth constraints, and real-time responsive UIs.

[tlrobinson]

> My connection is a sub 3ms ping to the nearby datacenters, what exactly is the bottleneck?

Heh, tell that to someone in, say, Australia.