Absolutely, it is an embarrassment that we design systems that continue to neglect this fact and, worse still, we judge and punish folks who have to interact with them at the "attention" end for mistakes.
In some critical attention places it is possible to "engineer" a bit more reliability into human systems with crutches like shifts and incentives (the military sometimes succeeds at this for mission critical applications), but in most it is a failure of system designers and software developers.
"You're using a suspiciously old browser" and I'm on Chrome 143.0.7499.42.
I guess the content of the website is not that important then.
Sometimes it's better not to think of it as the human neural net 'failing to notice things'. You're just setting yourself up for a long list of exceptions.
Instead, consider it as attempting to extract singular pieces of information that fall outside the norm.
(And do so from a complex, noisy, or even outright adversarial environment,under suboptimal conditions, possibly even below the noise floor. )
With that framing it's actually pretty amazing that people DO notice as much as they do! ;-)