Going by share of daily transactions probably isn't the best way to measure this as it's mostly going to reflect the usage decisions of the rich who spend lots of money. And there are many cash transactions that simply aren't recorded anywhere. Many, many more. If you go by number of people I think the amount of cash usage would be much higher in the USA. I don't have experience elsewhere. But 16% only? That's absurd. It does not at all reflect my lived experience. I do acknowledge that in high population density areas cash seems less prevalent. But most people I know use cash. I use cash primarily.
I do think it's also somewhat generational. I'm at the older end of Generation X. I grew up paying cash (or writing checks) for almost everything, didn't really use credit cards until my late 20s/early 30s. There were a lot of places that didn't accept credit cards back then, such as most fast food restaurants. But I switched to cards mostly out of convenience as soon as most places accepted them.
I notice a lot of people older than me (Baby Boomers and older) still pay cash more often.
And lower income people use cash a lot, I presume because they are unbanked or can't get a credit card.
I use cash because it's more convenient, faster, and I can use it anywhere rather than just in transactions from corporation to corporation. And I can use it any time rather than just when all telecommunications are working perfectly. And cash still works even when $state does some silly political blockade of transactions for $industry for performative reasons. And cash doesn't cost extra to use every time or have fees or have other rent seeking mechanisms. And when I pay in cash my behavior isn't sold to third party companies to profile and exploit me.
I really don't understand the preference to use corporate payment services. What is the upside? Is it security thing in high population density areas? Do you not use money so muggers won't be tempted to rob you?