I’d say it’s very much not besides the point. Like I wrote above, the boom is at the same time a physical barrier and represents a legal restriction. I.e. the law says you can’t pass the boom (unless it’s an emergency). So access=no on the connecting road is perfectly fine.
That particular boom that I linked to is on a motorway. Walking on motorways is against the law. So access=no in OSM. Doesn’t matter what I can physically do. I could scale most chain-link fences and climb over walls with a ladder. Of course anyone can break the law. So all legal restrictions are vacuously and tautologically only “practical” in that sense. I should say, that although this discussion is somewhat off-topic to the OP, this point is precisely why I think a value like =practical on the access= -key is a fundamentally bad idea. As established, emergency vehicles are allowed to ignore legal restrictions and drive anywhere they can (like cut through grass areas between roads). We don’t tag either of those facts.
Is this really something worth tagging? Sure, I’ve once seen a picture of a police car that drove through a hedge. Wouldn’t the material= tag on a barrier= indicate which barriers are easy to demolish with a car? As for specifically emergency-retractable barriers (like the boom I linked to), why wouldn’t access=emergency suffice?