Yes the prime meridian is somewhat arbitrary and a historical legacy of British imperialism-but replacing it with something just as arbitrary-but also idiosyncratic-is even worse.

The current system has the advantage that the international dateline goes through a relatively unpopulated region of the Pacific Ocean. I’ve thought before the longitudinal midpoint of the Afro-Eurasian landmass might be a less arbitrary (albeit still Old World-centric) prime meridian-but it would put the international dateline in a less convenient spot. And the costs of changing outweigh any possible benefit