TL
R, so if what I say has been stated already, I apologize.
My first Canon DSLRs--well, if I'm honest my first SLR was a Minolta, the I moved to Nikon when that got stolen, but that was 30 yrs ago--and I do agree that the Canon lens lineup is amazing. I got back into photography with a passion in 2009. I had a 40D. I added a Nikon D90 because it was ranked so highly on DXOMarks. It was better in some ways than the Canon--the 40D was boring but completely reliable--but trailed in certain aspects. I just looked back on some of my shots, and--shocking surprise--the Canon's skin tones were better. However, that may have been as much if not more due to the lenses. On Canon, I shot with the 135L, 85 1.2 L II, and 100mm L. It took me a while before I acquire pro-grade Nikon lenses.
I continued to shoot dual systems for most of the last 9 years. I loved the DR of the Nikons (I moved to D800E then D800) but still preferred the ergonomics of the Canons. Nikon continued to improve in multiple areas including color, but I did not see similar improvements on the Canon side.
By last year, I sold my Canon 5DM3 and was down to just the 80D. I was primarily a Nikon guy, but wasn't ready to give up my Canon glass. The 80D showed promise and, from what I heard, the 5DMIV had closed the gap even more. If Canon repeated their history of not releasing a camera with inferior IQ, then the 6DMII would be at least as good. That entry-level FF body would nicely compliment my Nikon kit. But that was not to be. To say that I was disappointed would be an understatement. I won't rehash all my negative thoughts about this offering, suffice to say that I finally considered selling my Canon lenses.
Then Sony released the A7rIII. I was reticent about working with a third system, but the possibility of a high-megapixel body with excellent AF, state-of-the-art IQ (both at base and high-ISO) that could shoot 10 fps was extremely enticing. What closed the deal was the ability to adapt my Canon class.
To keep it short, the transition has been extremely successful. The Sony is excellent with the Metabones adapter. I can shoot my 24-70L II and 100-400L II lenses for everything except birds in flight, and erratic action shots. Okay, the camera also struggle with adapted lenses in low-light photography. So, it is impossible to completely rely on Canon glass, but it is a fine short-term solution.
But the image quality. All I can say is, Wow! Color is superb straight out of camera and requires little PP. Skin tones are excellent, far better than Nikon. I may even like them better than Canon's, but I'm still experimenting.
What I've stated is not groundbreaking. Canon is producing cameras with IQ tech from 2011-12. Competitors are hungrier and have moved on. I'm glad that I've been in a position to take advantage of the advances.
So, to address the topic on the table, does Canon need to innovate more? For commercial success, probably not. Canon continues to release phenomenal glass--the 35L II is a prime example (pun intended)--and their service to pros is best of breed. Moreover, their marketing, name recognition, and ubiquitous presence at major sporting events almost assures their continued dominance for another decade.
But that's not the same question as should I continue to support them. I'm seeing tremendous improvements in usefulness, functionality, and IQ over my 5DMIII. I don't know if the Sony makes me a better photographer, but I do know that I leave a shoot with more keepers and IQ (rendition, clarity, DR, and resolution) that I never dreamed up with earlier kits.