Iphone SIM cannot be used elsewhere

While Iphones are extremely popular, one of the main disadvantages of using a Iphone is that a microsim has to be used. The SIM provided by the ISP will be modified or cut to fit into the IPhone SIM slot and then it cannot be directly used elsewhere on other conventional mobile phones.
So if a person is facing a problem with his or her main phone or mobile provider, and would like to test an alterative connection, they cannot use the IPhone sim with the mobile phone. So while some security agencies label a person with multiple sims as a security threat, they do not take into account the fact that the iphone sim cannot be used anywhere else and if a landline connection is not available, the mobile phone is the only way to contact and communicate.