It occurs to me now that this kind of round brought together two things largely lost today, at any rate in the UK:
a) It framed working-class people - specifically manual workers - as competent and discerning experts, and deferred to their judgement. Today, they are generally subject to what we might call the bourgeois gaze, whether hostile, condescending or romanticised. Not that those weren't also possible perspectives in the 1970s, but they were counterbalanced in a way we seldom see today.
b) It showcased manufacturing industry, at a time when that accounted for a much larger percentage of the economy. Part of the difference is of course technological: fiddly tasks are done by computers. But if I try to imagine a Generation Game or even a What's My Line? today, almost everyone is either working in an Amazon warehouse or sitting at their computer ordering things from Amazon, neither of which makes for great charades.
Necessary caveat: there are of course still skilled jobs in manual labour; but when did you last see a factory worker demonstrate their craft on prime-time, Saturday-night television?