I imagine sometime in 2030 when a 60 yo uncle/aunty sees this "38 people are looking at it", calmly right clicks on the HTML elements and sees the use of math.random and says "Nope, bye bye stupid website".
I think these tricks are closing on their end of life as percentage of internet-native people are increasing.
I think it's natural to feel like the populace is heading to a more competent place as the elderly age out, but anecdotally I think the opposite might be true. I've met kids in middle/high school who didn't understand how to do rudimentary OS operations, resolve email disconnections, update apps that didn't come from a store etc. The worst was when I taught a semester as an adjunct. Most of my students simply were unable to zip files together and send them as an attachment... Internet native in the iOS era is seemingly much worse than the XP era
It'd be difficult to infer that Math.random was used, purely by the element inspector. You'd actually have to sift through JavaScript code, which may or may not be minified (likely so, though).
The next generation are being raised on iPads, computer literacy is plummeting because they're only exposed to appliances, not real computers. It's sad, but it's good for our job security!
I think these tricks are closing on their end of life as percentage of internet-native people are increasing.