Lamar's a great generational talent quarterback but the truth is that he's just not a playoff performer...yet at least.
He's similar to Dak, who is a great quarterback as well but not a playoff performer either.
Obviously, it's not all on them for their postseason woes but at the same, neither one of them has played the type of game needed to go the distance in the postseason. Despite losing, reaching the AFC championship was a step up for Lamar but he still has some ways to go to reach that next level.
Better luck next year.
I will say that the way KC has played this year...I'd say their run to the Superbowl this go around has more to do with luck being on their side than anything, this is the weakest Chiefs team to reach the Superbowl. Nobody would envisioned them going this far considering how bleak things looked for them a few weeks before Wildcard weekend.