I will choose a product. If you have a good and unique product, most of the time it works for you. With service, in my experience, there is always more competition to beat
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