[em-bee]

so in essence your argument is that management needs to care about performance because most end users have devices that are not powerful enough to process all that javascript, based on this technical argument i found hidden in a footnote:

JavaScript-delivered UI strips the browser of its ability to meaningfully reorder and slice up work so that it prioritises responsiveness and smooth animations. JavaScript is the "fuck it, we'll do it live" way to construct UI, and stresses the relative performance of a single core more than competing approaches. Because JavaScript is, byte for byte, the most expensive thing you can ask a browser to process

that's fine. as an independent developer i don't care much for the management problems in large teams, so maybe this topic is not for me. i need to make the tradeoffs between engineering and product performance, development cost and client budget all by myself, and hence am looking to technical solutions to find the right tradeoff.

what i am missing on the technical side of the argument is how "fuck it, we'll do it live" relates to latency.

my expectation is that while device performance increases continuously and becomes cheaper, latency on the other hand does not improve as fast.

to put it drastically: people in rural africa or india have smart phones from the 2010s but internet connectivity from the 1990s

[slightlyoff]

Device performance has been growing in diversity as we approach smartphone saturation (the last couple of hundred million flipphones getting traded for < $100 low-end smartphones). I'm working on an update to this series, but here's a recap from last year:

https://infrequently.org/2021/03/the-performance-inequality-...

As this relates to latency, JS-mediated UI is slower to materialize for a host of reasons, not least of all the problems with getting it across the wire (as you note). Naive SPA designs tend to serialize what should be parallel (data fetching and shell setup). Getting better at this requires more sophistication, whereas teams that stick to basic HTML + light progressive enhancement tend to end up with simpler systems that are faster for light-to-medium session depths and are easier to diagnose/fix when things go sideways.