I've had yeast stop working after a few months unrefrigerated, but refrigerated it seems to last for years, at least, that's my perception.
I'd only advise somebody to bother to proof if they know the yeast I'm using is older than a few months opened unrefrigerated, but I habitually check it anyway.
Yes if you are an enthusiast and you have experience working with a given yeast, then you can skip the proofing step based on your own judgement.
But if any home cook simply reads "you don't need to proof yeast" and interprets it as another one of those cooking myths like 'sealing' a steak, they are likely to make a catastrophic mistake one day.
I'd only advise somebody to bother to proof if they know the yeast I'm using is older than a few months opened unrefrigerated, but I habitually check it anyway.