Elected officials take an oath to support and defend the constitution of the United States. The oldest members of the House of Representatives and the Senate are more than one-third the age of the document itself.
The constitution was written in 1787. It will celebrate 240 years next year. One-third of that is 80 years. Chuck Grassley is 93. Multiple other members are over 80. Some seem like beloved elder statesmen. Others seem like stubborn old farts who don't know when to quit.
We look at the world from our own era. New generations come of age having experienced technology and creature comforts, world events and social trends from their own childhood onward. Everything else is history. Studying history is good, but life experience fills it out. Thus an old person can tell you how it worked before and has contributed to the creation of the present in ways both bad and good. A young perspective is essential, but so is experience in operating a system laid out almost two and a half centuries ago.
The constitution itself has evolved. Amendments have been added to refine its definitions of freedom and the scope of powers. Part of what makes it a living document is that ability to adapt to social change. It needs old friends and new ones to help it along. Tradition for its own sake is obstructive dogma. Established practices aren't necessarily dogmatic traditions. Seasoned operators need input from younger generations, but aren't magically rendered useless just by their age.
Term limits seem appealing to people who haven't really thought about the problem. All a term limit does is make a legislator ineffective for the second half of their last term. If you know they only have so long, they have no influence to enact change that you might support. Meanwhile, you have no guarantee that the replacement you have in mind -- if you actually do -- will get in and be able to get you what you want. Corrupt candidates who con their way into office will have to act fast, knowing that they have a solid time limit.
We can reform elections and government to make the side hustles of political office less lucrative. That will winnow the field to the ones most interested in policy more than profit. Judge the minds of elected officials by what they actually do. Make every campaign a question and answer period where real people ask about the things that matter to them, and candidates answer. Get rid of the slick ads.
The First Amendment makes it nearly impossible to dial down the volume of political analysis dumped on us constantly. Propaganda is just an editorial position. You have to learn to sort through that mess for yourself.
The basics haven't changed in centuries. A government that actually cares for its citizens will establish justice, insure domestic tranquility, provide for the common defense, and promote the general welfare, even if the rest of the national structure doesn't call for a more perfect union of individual states, or feel the need to state explicitly that the blessings of liberty belong to the citizens now and forever. The technology might change. The definition of who qualifies for full citizenship certainly has changed in this country since its founding. But an old person is just a young person with a whole lot of miles on them. Just like old cars: some of them weren't that great when they were new. Some of them hold up better than others. The ageist rant against officials strictly based on their model year is not productive. Maybe it's not entirely a bad thing to have someone in office who was actually bullied by Thomas Jefferson in grade school.
I'm very happy to see the influx of young people and women in the current crop of election winners. From way back in the late 1970s I looked forward to seeing better gender balance in leadership. Clearly I was in the minority. And I never had what you would call a platform of any kind. I just observed and wondered why voters couldn't shake their ingrained sexism. You just have to wait for the idea to form in enough minds. Unfortunately, it also requires decades of bad decisions by the men in power finally to crack the myth that a man is always superior. It has taken the worst president in American history (so far), who is also a completely odious human being, surrounding himself with people sleazy enough to be fine with that.
Not that a woman or minority person is inherently better than a white man. They're just not inherently worse. It isn't even that elected government should reflect the proportions of the population they are hired to work for. They need to make the effort not to work against any of them. Human needs are human needs. That principle exists independently of age.