Talking about the irretrievability of individuals in Software

In the past, my understanding of software development was people-oriented and was deeply influenced by the books peopleware. On the other hand, in actual development, the flow of team members is inevitable, this is a very deep contradiction that has plagued me for a long time. Now, the new project is about to begin, and these basic problems seem very important again. I thought of this problem again on the way home yesterday, with occasional gains.

If too much emphasis is placed on the irretrievability of individuals in software development, this is actually equivalent to ignoring a great risk, it is completely an "Ostrich" approach. This problem should be divided into two parts. How to score? From this point of view, each person in the organization should be divided into two parts: one is his/her personal part, mainly including ability and knowledge, and the other is what he has done in the project. If personnel changes occur, the first part will inevitably be lost, and the second part will not be affected in ideal conditions. How to enable tacit knowledge to become explicit and how to ensure personal work through process management is not an irreplaceable task for project management.