Fujifilm X-T10 has a 16.0MP APS-C (23.6 x 15.6 mm ) sized CMOS X-TRANS II sensor and features EXR Processor II processor. On the other hand, Canon R5 has a 45.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Digic X processor.
Canon R5's sensor provides 29MP more than Fujifilm X-T10'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 X-T10 and R5 sensor size comparison.
As seen above, Canon R5 has a 2.3x Larger sensor area than Fujifilm X-T10. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.