A lot of money that is used to pay for services at retirement, pension schemes etc, use money that is invested in businesses which generate profit from sales or selling services. Some comes from savings accounts in banks which are used to loan money at interest. Long term capital growth from investment schemes is most guaranteed in having shares in companies making and selling something worthwhile.
It is interesting, no pun intended, that when the world banking system was on the brink of collapse 10 years ago, all governments and their financial regulating bodies went to what is called ZERO INTEREST economies, bank interest rates at 0.5% or so, much lower that what they had, 5%, 10% etc.
Sidqi take note- it was not Jawaid or his Qur'an that reduced interest rates so that economies stabilised, but sound economic principles. If you can get money out of bank savings accounts because 0.5% interest does not make you money from money, it puts more money in the economy to spend, use appropriately and invest in proper companies. So Riba based economies went to more trade orientated ones to keep themselves from collapsing. The vested interests in riba systems have to bide their time before they start reaping their money from money rewards until the next crisis, which always affects, is 'paid' for, suffer most, the least well off.
Zero interest is US Treasury, Bank of England, France etc, thoughts and practical financial policy. This is the Qur'anic Thoughts.