DO PRODUCT DESIGNERS NEED UI/UX SKILLS?

Summary from the TLDR Design newsletter

Product designers do need UI/UX skills, because product design spans research, wireframes, prototypes, testing, and developer collaboration, and UI/UX principles apply at nearly every stage. UI covers what users see, while UX covers whether the product works, and a beautiful app nobody can figure out still fails. Designers need not master every corner, but skills in research, wireframing, prototyping, and usability testing help them read user behavior accurately and keep decisions grounded.