Do you have the f/4-7.1 IS STM version or the f/4 L version of that lens? The f/4 L is my favorite everyday lens, and I would choose it over the 35mm f/1.8 for the following reasons.
The R8 doesn't have In-Body Image Stabilization (IBIS) but the lens has an Image Stabilization switch. So, assuming you can always shoot at f/4, the lens IS will allow you to use slower shutter speeds with less light and still compensate for camera shake.
The 24-105mm zoom is great for urban walkabouts and country landscapes, and I can get some images that would be more difficult with the 35mm. There are some places in town where I don't *want* to be up close and personal, and having 105mm lets me shoot from a safer distance.
24mm isn't as wide as my 16mm f/2.8 lens, but it's usually wide enough (and obviously wider than 35mm) for great landscape shots.
The only downside with f/4 is the lack of bokeh background blur, but I don't really miss it on my walkabouts. (Also, some editing software will let you add that blur in post-processing.)