Maybe I’m misremembering, but Gobert disappeared in the playoffs at Utah too, didn’t he?
The evolution of Gobert has been interesting. Early in his career he dominated defensively around the basket but was a liability on the perimeter. He developed his PnR defense and became a good PnR defender. He developed his positioning to help him in switches and force players to shoot over the top of him more often. He became a a good switch defender.
This led to an adjustment of how teams attacked him defensively in the playoffs. The early years they just put him in PnR. This no longer worked well. So instead LAC isolated him. They went small with Marcus Morris and sent Morris, a three point shooter, to the corner. This forced Gobert outside of the paint as a help defender but also kept him off-ball as a PnR and switch defender where he was causing LAC problems. This neutralized Gobert.
Don Nelson did a similar thing to David Robinson in the playoffs in 1990 or 1991. Sometime around then. I think it was Alton Lister. You had the illegal defense rules then meaning you had to stay close to your man. Lister was not allowed past the three point line and would often stand 5 feet behind the three point line. Stoppign David Robinson from camping out in the paint against a non-shooter and disrupting the Warriors offense. This also disrupted the Spurs team defensive concepts which involved funneling drivers into the shot-blocking David Robinson. The Spurs defense collapsed. The Warriors had a big upset.
Only nowadays this is easier to do because of growth of three point shooting. You can pull opposing shot-blockers out of the paint and neutralize their defense easier.
Furthermore, you can do this against Gobert whose limited offensive game makes him incapable of punishing sturdy defensively-able forwards in switches consistently as Marcus Morris ably showed.
Utah lost that series against LAC because they game-planned around Gobert's defense. They isolated him. They removed him from Utah's defensive team concepts. And without Gobert there to protect all of Utah's bad defensive players, they were wide open for attack and attack LAC did beating Utah in style.