JS will fail to execute a lot more often than most people realise, e.g. due to poor network conditions, particularly if hosted on a different origin (first-party JS is far more reliable, and inline JS the most reliable).
> e.g. due to poor network conditions
Do you have any metrics on this? Seems like an extremely rare edge case.
Anecdotally, I haven't experienced it in years.
The (semi-old) UK stats said 1.1% failure rate, but somebody more recent said it had increased to 3%.
That's a lot.
Somebody said is a bad source. 3% failure seems too high given nearly everything requires JS.
"Everything requires this" does not mean "this is always available"!