where is micro plastic coming from?

Literally everywhere

And what would be a good lever to reduce that?

Many, many, many individual pieces of legislation

Bottle caps are not the answer for any of that.

If you've read what I've written, you would know I'm not saying that

So the result is barely any change in the amount of plastic introduced in the environment

Where it ends up is the most important thing

but people (like you) become complacent, because we added those cap straps after all!

Again, read. I, or anyone else reasonable in support of this, are not saying this is the silver bullet. It's one of the thousands of points of iterative improvement we need to make.

but it's far from being free

In terms of green legislation, this is literally as cheap as it gets

this exact bullshit makes people ignore the real problem. Your view is far too myopic.

You have clearly not comprehended my previous comments remotely correctly.