I am trying to assess whether philosophers not changing their minds is something that is desirable or not. On one hand, they represent their theses after long periods of introspection and studying. On the other hand, their virtue signaling propensity may relate to various ego ambitions.

Definitely, debate for the shake of debate feels like an excercise for the philosopher rather than identifying why different views exist and where these fall short. In the long term, it may lead to change of the philosopher. Given everybody keeps an open mind, I don't think that this is necessary a bad thing.