The Hong Kong protests were way over 3.5% with no change? 3.5% seems like an arbitrary threshold that's meant to be broken...
3.5% of what? There are international, national, provincial, and local authorities, each with different constituencies, all of which overlap to some degree.
The preferred method of coup by powerful external forces who finance them are color revolutions - usually via arming violent extremist groups with controlled opposition leaders. That’s about all I need to know.
An American analogy of your argument would be something like “but >3.5% of LA wanted policy XYZ, why didn’t it work”
-- used 10B world population for simplicity.