Intentionally blocking the way is obstructing traffic. Going slowly on a local road in the rightmost lane is not.
If you have the ability to stop any place and get out of the way, as cyclists do, then yes, yes it is. It absolutely is obstructing the natural flow of traffic needlessly.
Farming equipment is allowed on any such road and that stuff usually travels at roughly similar speeds as bicycles.
Farming equipment is not allowed to disrupt the normal flow of traffic either. And they design the roads accordingly. They put massive shoulders on roads with any significant traffic which must also carry farm traffic, to enable it to get out of the way. Roads with less traffic simply get dashed lines (assuming they're not one-lane roads, like the one I live on) so that you can pass tractors, so that they don't disrupt traffic flow either.
This really is not complicated. We have laws against disrupting the flow of traffic because disrupting the flow of traffic causes every kind of problem. It reduces throughput while increasing the risk of collision. And that's why cyclists who can't find the side of the road do. They want to cry about debris at the roadside, but guess what? I don't get to drive into someone else's lane to dodge debris in my lane. Buy appropriate tires and tubes, and run slime, like an adult.
There are not so many roads with actual minimum speed limit posted and only highways specifically restrict bicycles and farming equipment from them.
A posted minimum speed limit is not necessary to disrupt the normal flow of traffic, and be cited on that basis, so that's irrelevant, like most of your reasoning. And it doesn't matter where you are, you're not allowed to hold up traffic. And there are numerous places where you can ride a bicycle on a highway, it's freeways you're not allowed to ride on.
You are literally wrong about everything you said in your comment.