I think the amazing resolution delivered by the 35 f/1.4 II, 100-400L II, etc... that have come out within the past couple years goes to show that Canon has the lens technology available to do whatever they want. I think they release the technology on their time line or when they feel threatened.

The 35L had been eclipsed by both the Sigma. No problem, Canon releases the 35L II and is now king of the 35mms for the remainder of the design life of these lenses and is now much better per reviewers than Nikon's 35 f/1.4 offering.

The 100-400L had been a top seller for many years delivering very good results. Now, Tamron comes out with an equivalent lens for much less money and Sigma comes out with TWO lenses that are equivalent/better. No problem, Canon releases the 100-400L II and is better than the Tamron and Sigma entry level options and equivalent to the Sigma 150-600 Sport. Again, the 100-400L II is likely much better than Nikon's competitive offering.

There are other successes too. The 11-24L appears to be a technology demonstration to have an 11mm full frame lens that is that good. The 16-35 f/4 L is cost reasonable and quite possibly with the exception of the much more expensive Nikon 14-24, to be the best ultrawide zoom on the market.

I wouldn't be surprised if Canon could offer equivalent to Otus lenses if they really wanted to, but may not see the market for that level optic.

Dave