When making chocolate for candy what is the benefit of starting from scratch compared to simply double boiling existing chocolate bars and using that material?

I started making chocolates in shape trays a few years ago. My method for obtaining chocolate for the molds was to double boil chocolate bars, or chips.

It worked fine. I noticed, however,that the chocolate had a bit more propensity toward melting. Was this in my head?

The question that is raised by this is whether or not I should have started from scratch making the chocolate instead of turning someone else’s chocolate into liquid for pouring. If you know about these matters I’d like to hear your opinion.