Always leaning towards product due to the ability to scale.
But starting out with product is really hard as many people want to see successful use cases, case studies, etc. I found a done-for-you (DFY) approach a good way to solve the cold-start problem so I've been manually onboarding new users and setting up consultation work with some clients (which includes them using my product).
So far I've secured 3 different clients this way through the consultation method. I know it doesn't scale but it beats having 0 clients...
So I guess a mix is good at least for the start.
I’d choose a product business. Once established, a product can reach a wide audience with minimal ongoing effort, making it easier to automate and sustain.
I'll say service because from what I see (where the people around me are freelances) it's very flexible and the best part is where they can have more time for themselves, family, hobby, etc
Wisp CMS