Most redesigns are guesses in a nicer font. They change how a product looks without ever asking why users struggled with it in the first place.
Research is not optional
We watch real people attempt real tasks before we design the solution. The insights are rarely what the meeting predicted, and that is exactly the point.
A system, not a screen
A design system makes consistency the default and accessibility a baseline. It is what keeps the tenth screen as considered as the first.
If it tests badly with users, it is not done, however good it looks.