I have that impression too. Without having directly experienced it myself, it seems like a hellish system. Though it does at least seem like getting “purged” isn’t always final, and that execution is the last choice.

Xi Jinping himself got purged in his youth and spent that time living and working in the countryside and building his ‘man of the common people’ cred, then made it back into the CCP’s favor later. Though Xi was a princeling, his father was one of Mao’s inner circle, so he might have been untouchable and only at risk of exile and not actual execution for that reason, unlike most other CCP members and Chinese people.

And to be fair, US politicians spend most of their time fundraising for their next campaign, so in terms of total ability and time spent on the job it’s probably similar in both systems. But losing a power struggle in the US just means losing your election, and trying again in the next one. In the CCP there’s a wider range of consequences.

For anybody looking to get some understanding of Xi Jinping's life and ascension to power, I'd recommend listening to "The Prince: Searching for Xi Jinping" from the Economist: https://www.economist.com/theprincepod