DJI Osmo Action 3 has a
12.0MP (1/1. ) sized CMOS sensor . On the other hand, GoPro Hero11 Black has a
27.0MP (1/1. ) sized CMOS sensor .
GoPro Hero11 Black's sensor provides 15MP more than DJI Osmo Action 3's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the and Hero11 Black sensor size comparison.
DJI Osmo Action 3 and GoPro Hero11 Black have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.