You are right. Lidar is the right answer _right now_, because alternative requires too much computation. SLAM, Visual Odometry, Structure from Motion, Multiple View Stereo, PMVS, CMVS, or even raw NNs will replace Lidar when computation gets cheap and compact enough.
Even that isn't sure. Certification is a huge barrier, and simple systems win there. And once lidar has proven itself and gained enough miles, it would be hard to change, just for cost savings.
