SIM cards have been around forever but soon, this might change. From the original SIM cards to micro and nano, the only thing to change has been their size. Apple has been the leader in pushing those changes and now they want to get rid of removable SIM cards altogether. As history shows, Apple gets what Apple wants. This time, they want to introduce static built-in SIMs. Static meaning the cards are not going to be removable, similar to their policy when it comes to batteries. However, the plan is to allow users to change their mobile carrier through a software.
The problem lies in the stubbornness of the carriers. The market is already segmented with the micro- and nano-SIMs being used to cater customers of Apple. Many of the other mobile device manufacturers have had to catch up and follow the trends, rather than create them. Back to carriers, not all of them are quick to introduce SIMs that fit the new Apple products and the only way to fit them is by using fiddly resizing tools. All these different standards do not really help customers but in the end Apple keep using their influence to hassle their competitors out of the way.
The newly proposed built-in SIM will still make changing carriers easy. With the help of software, once click will be all that is required. How many carriers will join the new standard is yet to be seen. One thing is for sure though, switch carriers will be easier than ever while changing phones, not so much.
According to The Verge