[davidmanze]

I think the word "lead" does not apply to both Nikon and Canon in this market segment. Both are distant followers at best.

Canon has high-end lenses but no camera to match. There are no affordable ultra-wide nor tele lenses (Ok, there's the Samyang 14 if you like to collect breadcrumbs).

Nikon is not too bad from my perspective actually but the question remains why bothering with a secondary platform in the first place.

Of course, the die-hards will buy them anyway but that's more an emotional decision than anything else. Of course, there's nothing wrong with emotional purchases. That's the business model of many brands.

When I said "lead" that was between Canon and Nikon ..... not leading the overall market ....... the race between the two big DSLR companies ..... 

  What about the upcoming EOS R5 ?
 
 Are you asking why Nikon has taken the step towards ML?