ChatGPT is a language processor, not a source of fact. Garbage in, garbage out. That answer attributes to the sensor certain properties that are due to the choice of lens. In particular:
1. The scene lighting, angle of view, lens opening, and shutter speed control the amount of light captured. The sensor is along for the ride.
2. The dimension of the lens opening and angle of view determines the depth of field. Again, the sensor is along for the ride.
3. A larger sensor does not provide more control. It provides more flexibility with regard to lighting conditions. But within a given range of lighting and shooting conditions, the actual control of the image is the same. If you fix scene lighting, angle of view, the diameter of the lens opening, and shutter speed, then sensor size doesn't matter.
This stuff has been hashed to death on this forum.
This is all true, but not terribly relevant in practice.
For instance, there aren't any F0.5-0.7 AF lenses for M43. However, plenty of F1.0-1.4 AF lenses for 35mm sensor format systems exist.
Thus, in real-world use where comparable lenses tend to have roughly the same f-ratio, and not the same physical lens opening, a 35mm system provides more control of DOF, gathers more light, etc.
A photographer is unlikely to build their own AF 25/0.6 M43 lens, so if they need this degree of control, their only option is to move to a camera with a larger sensor. So this idea that the sensor size is meaningless only applies if the criteria have been artificially restricted to what is possible in the M43 system.
Going further, in the cases where M43 lenses do exist with comparable physical openings, the M43 lenses are usually bigger, heavier, and more expensive. So not only is the system inherently disadvantaged when it comes to the amount of control, it's generally at a disadvantage when all things are equal as well.
So the chatbot's advice may be technically less correct than yours, but it's more useful to the average person who may read it.