You have a point that a few weeks of agency-style user research at the beginning of a project won’t always produce the most actionable knowledge, but your argument that ‘user research is overrated’ is rooted in a flawed understanding of research. The best user research teams working within product or service companies spend a lot of their time doing very different kinds of research than you describe here. It often includes strategic research around product-market fit, adjacent market research, investigating WHY important behaviours differ across segments, and so on. In the wake of a product release, it also often involves research not just on usability, but on why usage patterns take the form they do, what unknowns were not incorporated in the last build and that might make for good next hypotheses to explore, and so on. When a research team does this well, their output can be of huge strategic importance.