I host my personal blog on https://www.mcherm.com because to me it's worth a few dollars every few years for domain registration plus a few cents a month (I don't get much traffic) for AWS hosting in order to make it clear that the site is fully owned by me and not be dependent on someone else (like medium) who may have their own agenda.

Self-hosted is really cheap. So I guess it IS the proficiency signaling and the independence... but for me, those are well worth the cost.