Seems to me it’s pretty straight forward hyperbole.

If something is causing you to be a worse person, distance yourself or get rid of it. It shouldn’t really take getting rid of body parts to get there.

It’s like if someone said “I can’t stop playing WoW and neglecting my family” and you tell them “You can’t stop eh? Maybe you should cut off your hands, maybe then you could stop?” It makes them consider what “can’t” really means. In the spectrum of simply walking away from the vice that is making you worse person to making it physically impossible to engage in said vice, maybe it really isn’t impossible to give it up without resorting to such drastic methods.

That I would say is the least controversial of the things Jesus has said.