People rarely vote for individuals. Instead they usually vote for parties.

This is certainly true in the UK. I suspect it's the case in the USA and most other democracies.

80% of individuals are re-elected in the house, in part because power structures reward seniority and create path-dependency, so the older your guy the he can "bring home the bacon" (aka, pork) to his constituents.

tldr, not true in the us. totally different system.