Single-party systems by definition have either rule-by-decree or rule-by-consensus as a feature; so I’m not even sure the “rule of law” applies in the same sens

Single-party systems by definition have either rule-by-decree or rule-by-consensus as a feature; so I’m not even sure the “rule of law” applies in the same sense when the rules are that the people in power are a hegemony that can change the rules whenever they want. Because those who abuse power often do it through selective enforcement, and because the population has no “acceptable” way to depose those who abuse power, you get a situation where the things you do matter less than who you are. I wouldn’t claim rule of law systems are immune to this type of influence, but a feature of a strong democracy is having checks and balances on who writes the rules vs who enforces them. You don’t have that in China, and there are definitely different sets of rules for different people.