People not only earn interest on their savings, but they also borrow money – for example, if they buy a house. And the results show that the advantages offset the disadvantages. So there’s no reason to complain? Yes there is, because of course not everyone benefits. All monetary policy decisions have 1/3  BIS central bankers' speeches  undesirable distributional effects as well.
Consider, for example, the equity markets, where prices have risen dramatically. In Germany, those suffering most from the low interest rates are middle-aged people who own a small fortune and have invested it largely in savings accounts and in interest-bearing securities – i.e. it’s not very diversified. Are you telling Germans that their money would be better invested in shares?