To play the devil's advocate, imagine if politicians (US senators / House members) could live for and hold their positions for a thousand years... I don't know if that is a good thing.
Or Xi of Mainland China...
Or Xi of Mainland China...
I think it's a good thing: if the people continue to elect them, then obviously the people want those politicians to continue representing them for that long. Why should they be deprived of that? Objecting to this seems like objecting to democracy.
If this produces bad results long-term, that's the fault of the voters. Democratic systems are only as good as the voters who choose its leaders. When the voters are idiots, you get bad leaders. If the people don't like their 1000-year-old senator, they should vote for someone else. As we've seen in the USA, people don't have much trouble voting for a new President when they're mad at the current one for whatever reason (and the US also switched many seats in Congress in that same election).
>Or Xi of Mainland China...
Unfortunately, that's a possibility too, but by the same token, if Deng Xiaoping had been immortal, he could have stayed in that position and Xi might never have gained power and things in China (and worldwide in things related to China) would be a lot better right now.
Basically, your objection is one I usually see raised when the idea of immortality or radical life-extension comes up, but I honestly don't see how it'd be that much different either way.