Canon R100 has a
24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features Digic 8 processor. On the other hand, Fujifilm X-T30 III has a
26.0MP APS-C (23.5 x 15.6 mm ) sized X-Trans CMOS sensor and features X-Processor 4 processor.
One other difference between these two cameras that is worth mentioning is that Fujifilm X-T30 III's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the R100 and X-T30 III sensor size comparison.
Sensor Size and Resolution Comparison image of Canon R100 and Fujifilm X-T30 III Cameras
As seen above, Fujifilm X-T30 III has a 1.1x Larger sensor area than Canon R100. 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.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Canon R100
or the
Fujifilm X-T30 III ,
including hyperfocal distance.