Yeah, this is a common-sense question, or should be, and as Jess just said, the answer to this question is not a static or definite one, and saying that your own dragon "Jumps off of things all the time, like desks, couches, beds, etc. and is fine" is not a very good answer at all in my opinion. I'm not trying to criticize anyone that answered this question before Jess did, but it would be completely irresponsible to answer it in the way that it was answered before Jess.
You absolutely cannot assume that a Bearded Dragon of any size is going to be perfectly fine jumping off of couches, beds, desks, etc. simply because someone else's Dragon is "fine" doing this, or so they say...and they should not at all assume that their Dragons are always going to be fine jumping off of couches, beds, desks, etc. all the time just because they have been "fine" so far...And carpeting should not give you any kind of false-sense of security, as if your Dragon falls off of a bed that is 3-4 feet off the ground onto a carpeted floor, do you really think that means he'll be fine all the time? No, absolutely not!
A carpeted floor cannot prevent your Dragon from falling off of your bed in an odd way, can it? Nope. So if your Dragon jumps off the same bed, couch, desk, etc. that is 2-4 feet high onto a carpeted floor 100 times without a problem, and on the 101st time his he lands with his leg/foot in a twisted position or a leg/foot that is underneath him, then that will be the time he breaks his foot or leg. Or if on the 101st time he lands on his head and breaks his neck or spine, then that's the time that he'll end-up either dead or paralyzed for the rest of his life...You see what I'm getting at? Common sense people. Should you just feel comfortable with your 500 gram Bearded Dragon jumping off of your bed, couch, desk, table, or ANYTHING ELSE on a regular basis, from any height? NO, OF COURSE NOT! Not anymore comfortable than you'd feel letting your puppy, kitten, or baby do the same the thing...
So to me, the answer to this question is simply a matter of how responsible a Dragon owner you are. Why in the hell would you fell perfectly fine with your little 22", 500 gram adult Dragon (or younger/smaller) regularly jumping off of beds, couches, desks, tables, etc.? I don't get that at all...I mean, are you comfortable with your Dragon breaking/dislocating bones and being in pain? Are you comfortable with him paralyzing himself? Are you comfortable with paying a Reptile Specialist Vet hundreds if not thousands of dollars for x-rays and/or surgeries?
Unnecessary risks that can totally be prevented but that are ignored because nothing catastrophic has happened by allowing them to happen prior are just irresponsible and in my opinion stupid. It's your job as a pet owner to protect and care for your pets, and if you don't know the answer to this question then you shouldn't have a pet to begin with.