Each generation has new ideas and issues approaching them in their future, therefore each generation requires fresh minds that can bring society forwards in way that have not been perceived yet. But for those minds to come forwards and enhance society, they need to be voted into office in the first place.
Therefore, politicians staying in office and holding their position indefinitely is a huge hurdle to overcome if there are pressing matters the new generation has to face. For young politicians to come into office, they either have to become old in the process or have the mindset of their old party members to get promoted into relevant positions by them.
We need a term limit for all politicians, including many other relevant government positions. A healthy cut-off point would be 15 years; enough time to bring forwards significant change and short enough to not slow down the next generation of politicians tackling approaching problems.