AIRY3D has been developing a passive, single sensor depth solution that has lightweight power and compute requirements. With a single CMOS sensor you get both 2D and depth real-time streams.
I work at AIRY3D and we have advanced prototypes with some samples available for eval/purchase (limited supply). Definitely could be a replacement for RealSense for certain applications (eg under 1 meter range, and ideal for outdoors). Our sensors are ideal for machine vision and obstacle avoidance.
In the video above, we put a 2Mp Bayer sensor on a push cart to mimic the view from a floor cleaning robot. The distance to furniture, walls and thin objects such as cords under desks is clearly evident.
If you are interested, feel free to contact to contact me directly at pier-luc.tardif@airy3d.com