wullf, shooting sticks, monopods, bipods all require PRACTICE.
Bipods are only stable when you aren't forcing them to line up on your target. Some have swivel mounts that make things better, but it still requires practice in the field to learn how to use them properly. Improper usage can induce stress onto the stock and a miss.
Monopods come in various modes. Some are adjustable for height and attach directly to the sling mount on the fore end or have an attachment plate. I don't like them much.
The problem with attached monopods and bipods for the most part is if you're walking long distances the darn things are always in the way or digging into your back during carry.
I like an adjustable shooting stick with a "U" notch top. A good one costs over $50, about 1/3 the cost of a good bipod/monopod.
I have mine set for a standing, shot at a comfortable height.
I also use my shooting stick, which is made from aluminum/titanium as a walking stick. It only weighs a few ounces and is strong and rigid.
Again, I had to practice a lot to become steady on a shooting stick.
Most folks just don't realize that even though these implements help, they aren't magical.