> The World Championship match itself is problematic because it gives the defending champion a fairly huge advantage, in that they retain the title if they can draw out the match.

This has not been the case for quite a while. All of Carlsen's matches (Anand, Anand, Karjakjn, Caruana, Nepomniatchchi) had tie breakers in the format, to determine a guaranteed clear winner. The Karjakin and Caruana matches were decided in this way.