Methodologies or models?

As the survey shows, most teams prefer to use their own methodology, rather than take something ready.

Why is that?
Despite the fact that both XP and Scrum say that they “can be used as they are, out of the box” - in reality, this is not the case, and for the effective use of flexible methodologies it is necessary to adjust them for a long time under the conditions prevailing in the organization, under features of the project, etc. Since in all flexible methodologies there are more similarities than differences, it is often difficult to determine often what is used here? :)

Thus, it would be more correct to speak not about a specific methodology, but about the main models - a flexible, iterative, spiral, waterfall. Of these 4 clear leaders, there will be flexible and iterative models, moreover, flexible ones are more suitable for small ones and iterative ones for larger projects.