We all shared the same view with the west that China will eventually transform itself to democracy and we shall have harmony in 2047.....right until China shattered the promised universal suffrage.
Also, China had singlehandedly groom the separatist sentiments HK. Initially in 2014, there were only a handful of activists and they weren’t even treated seriously even within the pro-democracy circle. But lately you see Chinese state media started to put the separatist hat on every pro-democracy movement and figure. You can imagine people are extremely frustrated by this narrative and many young people started to wholeheartedly support independence (no matter how impossible it seems).