To play the devil's advocate with you and GP, term limits can often mean that congresspeople will be perpetual novices. Governing can be complex especially when seated on various committees like foreign affairs, CBO, etc. Older congresspeople who have accumulated years of experience have seen things go right, go wrong, and have learned a great deal about governing.
I think in tech we can attest to how disruption does not always mean good and how move fast and break things can go wrong.
To be clear, I don't disagree entirely with the idea of term limits or age limits, I just think the counter arguments deserve a fair amount of weight.