Basically, "UX Design" has become "Product Design" because almost no one wants to spend the time to evaluate what makes a good UX Designer. It's much easier to judge the visual aesthetic than to understand the process that made something comprehensible and an individuals skill at implementing and molding that process to get to that outcome. So they became lumped together. SF and "tech" companies need to scale and fast, so they assume "hey this person made something pretty, I'm sure the rest will fall into place" and now we are really just hiring for visual design. Even the companies that swear up and down they are about "process" you'll find little actual evidence or mention of it in their dribbble-bait portfolios. The excuse is often given "we move too fast to not ship and learn later", but a good design process should actual save time and resources in the end. As the company matures this weakness will come to light and then you'll get a combination of a dedicated research team and Product Managers actually completing the UX work with the Product Designers executing the vision in the form of juicy mockups. It seems like it's a significant step back. /rant
> Basically, "UX Design" has become "Product Design" ...
They are getting closer, but not quite. Consider two analogies:
1. Craigslist v. AirBnB to get a short term rental apartment. Both are arguably the same "product", the differentiation is that AirBnB has a much better UX experience.
2. eBay v. Sothebys to put goods on auction. Here, it's not really UX that differentiates them, it's product-market fit.
In the second example, a product designer would arguably be a better fit for differentiating the technical and business processes. A UX designer would then implement those ideas in the precise user flow.