Larry David contributed so much of his trademark awkwardness, but also was responsible for tying together multiple plot arcs at the end of episodes.

The episodes that all seemed to culminate perfectly on multiple levels as the credits rolled where largely his doing.

Similar to George learning to walk out on a high note, leading to outsized expectations. And that type of pressure is largely why David left the show.

ETA: If you've never watched curb your enthusiasm, watch a couple of episodes and you'll immediately recognize what was largely missing in the episodes once David left.