I agree that this is mainly due to IB being competitive. They may not be able to compete in some areas, but are very attractive where they can, like the interest rates.
While my previous answer wasn’t related to reasons why they require higher margin. Sure it’s for their own and everyone’s safety, and so be it. Still, other brokers may charge more for margin but you don’t have to use as much, so comparatively I may not even notice a large difference in interest rate on margin at IB vs another broker. Not sure about this, just suspecting so. May also depend on how to trade, and whether you may be able to utilize extra margin at other brokers to profit from it.
While my previous answer wasn’t related to reasons why they require higher margin. Sure it’s for their own and everyone’s safety, and so be it. Still, other brokers may charge more for margin but you don’t have to use as much, so comparatively I may not even notice a large difference in interest rate on margin at IB vs another broker. Not sure about this, just suspecting so. May also depend on how to trade, and whether you may be able to utilize extra margin at other brokers to profit from it.