High reelection rates for incumbent members of Congress

Some observers express concern about high reelection rates for incumbent members of Congress and have advocated for term limits as a way to formally remove longtime members of Congress. Why do you think these proposals for term limits are being advanced? Are there advantages to having long-serving members of Congress in office (e.g., when dealing with an entrenched bureaucracy)? What do recent election cycles say about the need for term limits? Are there other ideas for systemic reform such that challengers are placed on a more equal footing with incumbents?