I've wondered about these same things. There are so many variables most of which are dynamic. The US is not in a particularly strong (relatively, historically speaking) place right now. Much of the world is trying to crawl out from under the dominance of the USD. As you point out, the US and the west in general are trying to become less dependent on Chinese supply lines, but that will take a while. Socially and politically the US is nothing less than dysfunctional.

Then there's the question of when does a blockade become a blockade. How many forms can it take? I think at some point we're going to see China boarding more container ships and other carriers under the guise of protecting Taiwan from 'terrorists'. That's sort of a blockade light.

So basically just an extension of their current intimidation. Notice how they've been getting more aggressive towards the Philippines in the S. China Sea without the world really caring.

China could probably make a legal case for boarding ships anywhere in the territory it claims, particularly if there's some sort of preceding false flag event.

One thing is clear. Their trajectory over the last couple of decades and particularly in the last few years has been one of increasing intimidation and aggressiveness. That will continue, and as it's increasing, well, that increase will manifest in actions and policies that right now are not happening, but will happen.