By way of a contribution to this discussion, we have 5 or 6 turnstiles taking cash at every home match, and that will not change any time soon.
We also have a similar number scanning tickets. We are acutely aware that we have only been selling tickets for one full season - 21/22 - and we cannot expect people who having been paying cash for many years to automatically switch overnight.
It seems to me that clubs who are not selling out games are mad not to accept cash at the turnstiles on the day. Customers should have a choice, and clubs at our level are not in a position to turn away business.
That said, the more advance tickets we sell, the more likely we are to get people into the ground more quickly. Especially in the 15 minutes before kick off where we are always going to have a mad rush, no matter how often we encourage people to get there early!