I never understand the need to resist while giving KT or need to create dependency.
Be a person who is irreplaceable because of his knowledge of industry(domain) or technology and your work ethics.
Knowledge about a project or application can always be learnt by anyone but technology or industry knowledge and work ethics cannot be built easily.
You won't be disturbed during leaves due to dependency on you
Your leaves will also be approved as others can handle work during your leaves.
Moreover if you don't have dependency due to being a bottleneck you will not be overloaded with work.
You can grab better opportunities when you see them and you will be able to say that no dependency as such.
So I see more harm than benefits of creating dependency.
Speaking this from 15 years of experience I worked as both IC(developer) and manager as well in past few years.