When does designers get obsolete?

Short answer

When they stop having fun.

Long answer

The question I keep returning to is not about skills or tools. It is about orientation. Every two years, we go back and ask: are we having fun still? That is constantly like a North Star we have up.

The designers who go obsolete are the ones who accept the lanes drawn for them. UX stays here. Visual stays there. That shiny logo redesign is where it ends. But design does not end at the screen. The experience of your customer support is as much a determinant of how somebody perceives your brand as anything on the screen.

What keeps a designer alive is staying interested in seeing the work out in people's hands. The bits to atoms journey, how digital pieces move things in the real world. Lose that curiosity, and you are already obsolete.