I believe it has, indeed, been tried

Where? In former communist countries the workers didn't have any power after the seizing of the means of production, as now they were ruled by brutal dictatorships with powerful militaries who'd send you to the gulag for $REASON.

Hardly the envisioned "seizing the means of production" and more like "being seized for production".

Well said! Rarely do you see the description of Soviet state demand production vs anarchist syndicalism as concise and precise as this.

The idea of self governance in semi autonomous groups has been derided as primitive so thoroughly that the mere concept evokes fear and disgust

Truly we have centuries to undo these tropes of domination and competition as the only way to organize society

I've yet to see evidence that outcomes would ever be different

Where would you see that evidence if it was nevere done? Because it can't really be done.

Because the workers themselves don't have power to seize anything. The military is the one with the power to seize stuff come a revolution because they're the ones with a lot of big guns, not the workers. But now the workers themselves become part of the things being seized, to serve the military leadership, not the workers.

Workers get screwed either way.

With a couple of notable exceptions (Cambodia, and mid-90s North Korea) that still sounds like an improvement in their material conditions.