Islamic banking vs conventional banking: It is more about the Process
There is no need to define conventional banking. The concept of paper money was an innovation in the society and now that it prevails qualified muftis etc have studied this for years to differentiate the fundamental concepts as described in Islamic law against conventional laws of finance that are predominantly haram. Just because the end result is similar has got nothing to do with the methodology. You can make money in gambling and you can make money by trade. One is haram. One is halal.
How’s buying a car at interest/lease/Ijara from an Islamic bank different from buying it from other commercial banks, when you pay the extra amount at both banks? There is a huge difference between the two. The truth lies in the process. Just like you don’t eat chicken abroad but when you see a halal certificate you eat it. It has to do with the process. In terms of process, there is a huge difference. Also, how Nikkah papers are not just ceremonial and a contract that disavows Zina and makes sex halal. What is the difference between a wife and a girlfriend? Just a “contract “ (Nikkah nama) makes the girl halal for you. In Islamic banking, usually, a process has been defined as Islamic Banking whereas in any conventional bank it is not.