Historically, when a will maker wanted to change their will, a codicil was quite often the document used to achieve this change.
Codicils were often used where there were only relatively minor changes to a will. The reason for codicils existing was largely driven by technology in days gone by.
In particular where wills had to be physically typed, an amendment by way of codicil was a much easier process, rather than completely re-typing the entire will.
With the advent of computer technology, it is often significantly easier to simply amend an existing will in its entirety, rather than producing a codicil.
This technology evolution also avoids one of the significant difficulties with codicils – i.e. they could often be 'misplaced' and there was always the concern if one codicil had been done, whether there were any other additional further codicils that should also be searched for.
** For the trainspotters, ‘how does it feel’ is a line from The Chemical Brothers song ‘Let Forever Be’ from 1999.