Serving the people of the United States and the states they represent should be a privilege, not a career path. If our elected officials were less concerned with being reelected, perhaps they would be more focused on serving the needs of their constituency.
Term limits for the POTUS were set by practice, before the 22d Amendment, starting with George Washington. Thomas Jefferson endorsed the idea, saying if not for practice or the Constitution, the effective term could be for life.
Unfortunately, that's what's happened to our elected representatives. They have become, more or less, elected for life. The effect of this seems to be less representation for the people they server, and more about the continuing effort to advance their own "careers" and their respective political party.