It is easy to do something the same way we did it before. 

The previous time acts as a guide.

Using the same approach as last time gives us something to improve on. We can see the shortcomings and improve on them. 

We need to do less mental work when we use a tried and tested and optimised approach.

Using the same way as before avoids us challenging whether the way we’ve been doing things for all these iterations is still fit-for-purpose.

The same way as before gets us out of difficult negotiations with the other people who are also invested in the same-way-as-before approach.

And it avoids us having to do the hard work of imagining and creating something different.  Something better. Something more appropriate. Something that the system we are working in needs more than the same way as before.