The main advantage I can think of is you can just configure your nightly expensive CI jobs (running absolutely all e2e tests) to run against a static branch.

Another might be that git clone gets the "correct" branch by default. Might be important if your git repo gets cloned by sales, support or whatever for external demo purposes.

Anyway I don't think it makes a huge difference in complexity - it's rarely used for developers' workflows and doesn't even need to be updated that often.