The Innovator's Dilemma  is something that Steve Jobs seemed to have solved. How? Selling one product that cannibalizes sales of another from the same company was A-OK on his watch.
The iPod Mini was a perfectly fine device, yet Apple introduced the iPod Nano at the height of the Mini's popularity. The Nano had less storage , but it had solid state flash memory, and therefore was thinner yet.
How'd that work out for Apple? Just fine  - they kept about 80% marketshare for the entire life of dedicated digital music players in the market, and that market only went away when Apple brought out a phone so good that it made carrying a dedicated digital music player unnecessary.
Competing with themselves is a key piece in Apple's sustained success in a few markets. The iPhone 8 / X matchup shows they continue to not be afraid to do that with their phone, and I think that's a very healthy thing for their continued success... which also feeds into continued success of their ecosystem, including app developers (like myself!).
So they introduced the X right at the iPhone8's peak? I can believe that.
Apple has certainly done that in the past, used to be the best at it but this is the new Apple, not a technology company anymore but a lifestyle company and the product has suffered as a result.