You're attempting to use logic in a place where there is none.
2) it’s a lot less fun to talk or think (and may be dangerous to even try) about more realistic issues - like if you’re on the wrong side of the situation in Bosnia or Rawanda.
3) it’s the same kind of general process though, and some of the same tools can be useful to defend, escape, or repel.
And gold and diamonds got a LOT of people out of harms way that otherwise would be dead - at least from the 2 folks I knew that got out of Vietnam with their families when the south fell (and are probably alive today) only because they were able to bribe their way onto the boats using gold.
Think Argentine 90's hyper-inflation crisis. Think Venezuela economic colapse.
Heck! think Argentina RIGHT NOW.
If you think of it however as not needing to be rational, but more or from an evolutionary perspective ‘folks in the past who had similar types of fears and discomfort might have survived prior insane disasters that no one else expected to ever occur’ it might make more sense.
It doesn’t have to be rational. It doesn’t even have to help them survive or be successful most of the time. If it works even a little better and they survive when everyone else died because of their insane paranoia, those genes will propagate.
Most of us prepare for short-term disruptions that are far more likely than hordes of undead roaming the streets. If widespread societal collapse should actually happen, then having a strong local community, and knowing how to co-operate and communicate with one's neighbours is far more important than having enough canned tuna to last to Ragnarok and back. That being said, having survival skills and basic supplies can come in handy in a wide range of situations.
Personally, I'm preparing for more basic things like long power outages, extreme weather and supply chain disruptions. Sure, we got food, fuel and supplies for a few months at home, and it's been very handy during the pandemic, while being snowed in for a week a few winters ago, and when being without power for two days last summer -- I could keep working like any other day, and didn't lose any income.
Yes, that includes some cash. It's been handy a few times when the card terminals at the store wasn't working. Storing large piles of it seems an unnecessary risk, though.
The writer probably wanted to subtly refer to relevant Danish-American actress S.J. (a cryptic critique of the frugal accomplished Northern Europe?) in her statement "If I pay bucks for a movie ticket, I do not want to go there and think" (quoted from memory). Too subtle, let us not speak in riddles! (Even that «transphobia», presumably to be read as "fear of [monetary] transactions" - privacy, availability, inflation, currency as a token without intrinsic value: with such obscurity, little of the message can pass.)
Romero confirmed the depiction was that of "the revolution", where "the awake" realizes the vast majority is assimilated, but discovers "humanity" inside himself and decides that it is worth fighting to defend it, as the core hidden topic in the original work which provided the inspiration: Richard Matheson's I am Legend.
All of that installed in the social crisis of confusion, incompetence and violence seen as the core aspects of the '60 in the USA.
...Since we are discussing about cash, and surely you wanted to be on topic, I assume you meant to state "ghouls also renounce to privacy", worsening the scenario Romero originally depicted. Well noted.