IMO more accurate presence detection. Common sensors like PIR and cheaper doppler radar types can detect when there's motion, but not if a user is present but not moving in the detection area (e.g. sleeping or sitting). There's also open source projects that can track bluetooth wearables & phones to know who specifically is in a room, but these aren't able to detect people with no devices, say guests and kids.
The preferred approach at the moment is a combination of sensors to cover motion and person detection separately, which comes at a cost, both on your pocket and the time needed to get it working suitably for your needs, or maybe one of the more expensive radar sensors like the FP2 that can detect where in a space is occupied with higher accuracy than more affordable alternatives
The thermal cam is roughly in the same price range as the FP2 - however since it has I2C, something cheap like an ESP8266 can be used to turn it into a WiFi based presence detection sensor. Something like an ESP32 could be used to turn it into a presence detector and wearable tracker, negating the need for another separate sensor entirely.
Something like this would probably be quite close to plug and play for someone DIY focused, and wouldn't have the same problem as radar being able to see through walls to different areas, although this is somewhat solved by surrounding the rear of the sensor in foil with caveats.
I'm interested in how it performs outdoors in rain though, a lot of existing affordable sensors (except PIR) struggle a little in wet conditions, with doppler based ones not detecting anything
I have a steam deck, and while its somewhat portable, I wouldn't want to carry one just to use at a charging station, considering the alternative is a controller stashed away in the glovebox. Probably also would want to carry the deck whenever leaving the vehicle too, considering how common it is in certain regions for some tesla models to be broken into and boot emptied out (apparently preventable with a 3d printed shim).
With the crazy powerful GPUs in these cars IMO it's practically free to enable this functionality for the user when the car is stationary, on a screen that is much, much larger and with a nicer sound system compared to any handheld or phone