The Sony has a much better sensor than ANY aps-c Canon. Check DXOmark.com for raw sensor performance (this is the defacto standard.
Here is the DXO comparison of the sl2 (aka 200d) and the a6300:
https://www.dxomark.com/Cameras/Compare/Side-by-side/Canon-EOS-200D-versus-Sony-A6300___1171_1072
The overall score was 79 to 85, with the a6300 winning every category (color depth, ISO noise, and dynamic range). Canon has used less capable sensors going back a great many years. This is what prompted me to leave Canon back when the Nikon d300 was released, I compared to to a Canon 50d and well next thing you know all my stuff is for sale. Everytime I am about to a major upgrade I compare again. I keep two cameras for mostly video and one for mostly stills. Due to lens selection, the stills camera will always be a Nikon or a Canon (at least until Sony eventually cranks up the lens productions, and then maybe I'll include them in that comparison)
If you don't mind a larger format than the a6300, the gh3 and gh4 are in the same price range and are far and away better at video than either the Sony or the Canon.
I rented a gh4 and gh3 intending to buy the gh4. At the time the price difference was enough for a couple of decent prime lenses. I tried 4k video and hated working with it. It takes soo long and soo much storage for a fairly minor image bump unless you're on a event sized screen (in which case 1080p looks very fuzzy). The video focus speed of these two, was unmatched. Not because some yayhoo on youtube that no one has ever heard about, but because actual experts in the field tested it and have said so over and over. I use our GH for commercial events viewed by many 1000s.
Right now the gh3 is just under 500 at amazon. The gh4 is just under 900. Both will kick the Canon's and the Sony's butt in video. Both will finish 3rd in still image quality due to using a smaller sensor (m4/3 vs aps-c). The newer gh5 will about tie the Canon (overall raw sensor score of 77 vs 79) this despite being a much smaller sensor. Neither can compare to the Canon lineup for lenses (except Nikon, which has slightly more).
Here is the summary text from the DPreview.com review of the SL2.
Not good for those taking photos of subjects moving quickly or unpredictably. Moviemakers who want a decent set of video capture tools. This is because the video AF is not very good compared to its competitors.
The pro's were about it being small and having an optical viewfinder (which you can't use during video recording)
While on the a6300.
"Anyone wanting a tool that will let them take excellent images or 4K footage in a wide variety of circumstances."
The con's were about the menu system being complex.
SL2 78% over all, a6300 85% overall. Neither was at the bottom, the SL2 got a silver award while the a6300 got a gold.
These aren't fanboys with an axe to grind like the other fella here. But the most respected photography site.
Summary from gh4: (Score 85% and a gold medal)
Good for: Enthusiast film makers and anyone who cares as much about their movie footage as their still images.
Good for from gh3: (Score 79% and a gold medal)
Anyone looking for top-quality video as well as stills.