You probably need to step outside of your US-centric bubble if you are to comment on how university works outside of the US. There was a fairly large clue in the parent comment.
UK universities do currently hire people to do research and teach. And tenure is based on research not teaching. Teaching is seen as something that funds the operation to an extent. Some are excellent teachers. Some merely provide the material.
It works as is because researchers are not meaningfully impacted by having to do a few hours a week. And student get access to people in touch with the field. But it is not optimal having people who often are not good at teaching and/or don't particularly want to do it, taking lectures and tutorials.