When the model S was at its sales peak from 2013-2020, Lidar was still pretty expensive. So he put cameras in the original Teslas.

When Karpathy took over in 2018-ish, Tesla realized that all their advantages (dataset size, quality of researchers) was in the 2D realm. Waymo had been doing lidar for longer, seemed to have better 3d engineers & could keep upgrading lidar devices as they went.

Tesla's insistence on 2D cameras has to do with stubborn desperation more so than a willingness to play catch up. Elon needs 2D cameras to 'win' because even as early as 2019, he thought that it was too late to start playing catch up in 3D.