For sure, that tenon is not made correctly. One, it does not have a dove tail to match the dove tail on the chuck jaws. Two, it isn't wide enough, and should be another inch or so wider. Three, it is way too deep, which has it bottoming out in the chuck, and there is no contact with the shoulder of the bowl, so the leverage point is where the jaws meet the chuck.
Now, as for a recess, which is what I use 99.99% of the time, it will hold equally well as any tenon if it is made correctly, which is angle to match the chuck jaws, ample size for the bowl being turned, and ample shoulder for the jaws to expand into.
I have never understood the concept that a recess wastes more wood than a tenon. If the tenon and recess both measure 1/8 inch deep/tall, and you turn it off, they are exactly the same...
robo hippy