Trying to decide between PhD offers got me thinking about the goal of a PhD. I don't mean in a general sense (see here for an example), I mean about which area of research to prioritize. Of course, ideally, in a PhD you'd have an interesting topic AND you'd be using techniques you're interested in. However, if given the choice, I would choose to focus on mastering a technique I'm interested in (which can later be applied to other topics), rather than focus on a topic I'm interested in (where different techniques can be used later).
My thinking may be naive, but I believe if you gain the necessary experience with the techniques you're interested in, it will be more useful in the future than to specialize in a niche topic because changing topics after the PhD is easier/more common than finding a job using a technique you may be interested in but have limited experience with.
So I was wondering which made more of a difference in your experience: the techniques (lab skills, programming skills) you learned during the PhD or the (sub)topic you specialized in?