I agree. However, in the last game I noticed that Kessler really increased his hang time on his dunks. He is not jumping higher but now he takes off farther away from the rim and dunks with authority (instead of attempting weak, blockable finger rolls). I think that is because Walter became better at using his feet to push off for running dunks.The biggest thing Kessler will (likely) never have that Gobert did is the ability to dunk. He just isnt that good at rising up in traffic (not that Gobert was, but Gobert was long enough to overcome that, at least in his athletic prime).
Kessler has been quietly adding a lot to his skillset: better dunking, better passing out of the post, improved stamina, noticeably improved pick and roll execution... Even his 3-point shooting ability: it may never become one of his primary weapons but it would allow him to stay on the court when the Jazz try to pull a dominant center away from the basket. And, importantly, if Kessler is going to to play 32-34 minutes then occasional standing in the corner would allow him to catch his breath and have more energy for banging under the basket.