I doubt that you really think central banks, retail banks and the imf have no intention to abolish physical cash. Abolishing it is all upside for them.
For retailers (companies that accept payments) it's easier, faster, cheaper and safer ( zero risk of theft by staff or robbery). For regular people that pay it's easier, faster, more linear ( if you have to spend X now, you don't have to have withdrawn it from an ATM or bank before).
The only downsides are underbanked people and companies, which is an issue in itself and needs to be fixed regardless of cash availability (I'm talking in general, but even more so for developing countries and the US(wasn't it in the news recently that the US Postal Service is going to be cashing checks at some ridiculously expensive rate? Way to get in to the 19th century!)), and of course privacy, for which regulation is needed ( who has access to your payment/transaction data and in what cases) and it's solved for 90% of cases.
A debit card costs .10c and no %. A well implemented cryptocurrency would be even less.
(larger than now, how big a negative interest rate are you in favour of? Nevermind: I see from your other comment, 5%, immediate bank run territory.)
You realise lower financing costs do the opposite of encouraging long term thinking. The inflation cost is merely moved to deflation cost of cash.
What do you mean by a post capitalism system?
You realise that hyperinflation contributed to WW2, and that in the event of negative rates the rich move out of cash into another asset(like housing). See Roosevelt and the gold standard. I honestly doubt that negative rates would have avoided the Great Depression.
Wealth taxes also reduce inequality and can be more progressive than negative interest rates which hit middle income earners the hardest, who try to save for retirement.