The Hasselblad sensor on the Mavic 3 Pro is F2.8 on the fast end, but a larger sensor compared to the 3S F1.8 1-inch sensor, so all things considered it's probably pretty equal or negligible difference in low light.
LOL. Yeah. I HAVE a Mavic 3 Pro, not ecstatic about the 3S being better, but ... the drones keep improving. Maybe the Mavic 4 will be amazing in low light.