a position that has an 8 year lifespan

Legally. Notice any patterns lately about legal compliance?

that event is significantly less useful to new faces than it is to established politicians

Because voters are ill informed, careless, prejudiced, and operate more on name recognition than anything else, after party affiliation - straight ticket votes.

established politicians who are also known quantities that are most likely using those networks as well.

Players like Bernie Sanders should start “partnering up” by the time they reach 60 years of age, clearly making public appearances with a protoge under the age of 40 whose name gets tied to theirs at every possible opportunity - say Bernie’s protoge was Golda Schuster, let the public hear Bernie Sanders & Golda Schuster at every possible opportunity for 20+ years, when Bernie finally steps down, they can vote with confidence that Golda Schuster will carry on Bernie’s legacy faithfully, because that’s what they’ve been told for two+ decades. Thousands will still enter the ballot box, look at the choices and say to themselves “Golda Who?” but it would be a much better transition of power than we have today.

Cognition is a big part of competence

Yes, and I can only hope that our current system is somehow shielding us from the worst of the dementia driven choices that undobutedly are happening in D.C. every day.