I think History Learner hasn't Learned about tofu dregs construction yet. I'm pretty sure a good chunk of the PLA navy is more likely to sink itself rather than an enemy if it ever tried to fire a weapon.
Radar doesn't work well close to ground, or in bad weather. Also China has a problem with Tofu Dreg construction so their radars probably only have an effective range and/or endurance a fraction of specification.
The US has shown its bio-weapon policy to be weak with Covid. They could easily get away with dropping an epidemic on Taiwan, especially if they can get some US based pharmaceutical corporations involved.