Will negative interest rates push more people to be 'unbanked' (physical cash heavy) or into the crypto-currency space?

It is kind of amazing how markets and P2P crowds came up with a completely surprising and shocking answer in form of cryptocurrencies, which was completely improbable before. Satoshi's publication was during the Great Financial Crisis of 2008 but I cannot imagine that even he would have been able to foresee the absurd concept that negative interest rates are.

I don't see myself stashing assets under my mattresses. While cryptocurrencies seem to be perfectly suited to the task, actually much better than gold, which was supposed to play the role. But if you take cryptocurrency into account, what platforms do you usually use to have high passive income? I heard about all sorts of platforms for earning BTC, ETH & USDT like Nexo, BlockFi, Midas.Investments, Crypto.com, etc. Have you ever used these platforms? What platforms would you personally recommend?