Both in games with premium currencies like diamonds, and in real life with plastic cards and services, it's been shown time and again that the further you are from actual cash the more you spend.
This can't be emphasised enough and is, to my mind, a near complete explanation of the drive for cashless. We, as good consumers, will spend more in a cashless world.
When we were struggling to make ends meet after the dot com bust we slowly realised this, and came to draw out cash first for everything possible. If the cash wasn't there first, it did not get bought. I will still, nearing 20 years on, draw cash prior to shopping, or buying fuel etc. Debit cards get used online. The credit card lives in a drawer. Unused and balance free for years.