UK could have demanded a lease renewal from PRC as the price for switching recognition. Instead they just got some “alliance” against the Soviets and it is questionable what that actually delivered.
China doesn't like to take credit for that, but personally I believe its alliance with the West was instrumental in the collapse of the Soviet Union.
Giving HK back to China is an act of decolonization. Putting them under Taiwan and loading up the island with US weapons would not be.
PRC is itself a colonialist power. See all the Uighurs in concentration camps.
I don't want to devalue your experience, but Anglo powers have a terrible record of "colonialism for their own good", "we'll be greeted as liberators", etc.