At the time of the handover the world was in a unipolar moment. People though that we were converging on an “end of history” where every state was inevably moving towards democracy. The relative importance of the Chinese economy in world was a tiny fraction of where it is today. It was a mainstream opinion in Western circles that Hong Kong would “take over” Beijing rather than vice versa.
The whole Hong Kong scenario always seemed weird, utterly reminiscent of backroom negotiations and colonialism.