Is digital marketing certification worth it?

Absolutely, but it comes with a number of ifs and buts. There are a number of benefits associated with digital marketing certification like getting hands-on new techniques and tactics, practical knowledge, the know-how of latest trends, a clear path to a bright future, enhancement of your skills, better package, strengthening of CV and many more.
However, a certification is only viable if it teaches you the modernistic features about the field, gives you a practical knowledge, you are taught by professionals, is globally or widely accepted, gives you solid knowledge about what you are doing be it SMM, Content Curation, digital ads, SEO, video marketing, etc.