Again, you are ignoring reality.They are waiting for declaration of independence that will come at the time of their choosing, when all the pieces on the chessboard and checkers are all set. So, they very much control the trigger. Why not already? Because they're all busy re-orienting towards China. Putin probably threw a wrench in that plan by year or three.
SImilarly, applying your logic, one can ask why hasn't China unified Taiwan? What are they waiting for then?
The longer US/Taiwan waits, the worse the situation is for them.
1970s - Best fighter in Chinese inventory was J-7 - ROCAF had F-5, about equal, US had all kinds of superior aircraft
1980s - Earliest J-8s (nothing to write home about) and, ROCAF is about the same, US introduced F-18 Hornet and improving the F-15/16
1990s - PLAAF has early SARH-only BVR Su-27/J-11A acquired from Russia, ROCAF has Mirage 2000 with MICA Active AAM, F-16 with AIM-120 capability, F-CK-1 with TC-2, US finishing F-22
2000's - J-20, J-10C, J-16, J-15, J-16D etc. etc. Do I need to go on? ROCAF - many Mirage crashes due to age, upgraded F-16. US stops F-22 production and still ironing out issues with JSF/F-35 (program started in 90s)
Although for PLAAF, some of these are just variants, they are also uniquely new capabilities that did not exist 20 years ago (dedicated EW, carrier aviation, etc.)
This is just talking about the Air Force, not even navy, rocket force, army, or space. Can't overlook the fact that there was no Beidou constellation 20 years ago. Old DF series missiles were talking about dozens of m CEP at BEST. Now, they are able to hit the front door.
So what reorienting? Is Taiwan or the US waiting for China to build the second Death Star to declare independence? The longer it takes to reorient, it's going to be another dozens of ships and J-20s built, 1000s of missiles, rockets, drones, etc.
So right now PRC is enjoying a flow of investment capital from Taiwan into mainland China, flow of capital from the US into mainland China (Hi Elon! Hi Tim Cook!), and using this money to tangibly invest in the country (not just the military, but HSR, high tech manufacturing, poverty alleviation, etc.), meanwhile the whole world has to at the very least pay lip service to One-China policy, and China has the UNSC permanent seat. On top of this 40% of Taiwan exports are going to mainland China. You tell me what they are waiting for.