Security/Musl Question

[publiclewdness]

Often times I have seen people refer to PostmarketOS as a more secure option than other distros available and usually the reasons revolve around it being based off of Alpine Linux and using Musl. What makes Musl a better choice ? I tried to web search it but mostly get results of people talking about how it is faster or has cleaner code or takes up less space but not about security specifically. How would PostmarketOS stack up against Mobian or Graphene OS in the security department ? All three have full disk encryption as options but past that it gets into territory where people make vague statements but not much explanation.