Both Nikon and Canon have come out with new a new lens series for the new Mirrorless cameras. Lens mounts are both larger in diameter AND very close to the 'film plane' / sensor.
This gives a few technical advantages which can lead to better lenses, slightly more compact and even a SUB F1.0 Normal Lens.
As Nikon and Canon shift to Mirrorless, and they each currently have 2 models, they will slow down development and introduction of DSLR lenses.
The new Nikon 24-70 F4 is a very good lens. And measures as well as the F2.8 version which is fairly $$$.
Canon kit lens is the 24-105 F4 which is very nice, indeed.
The Big Three of Nikon, Canon and Sony are all aggressively pursuing the ever shrinking number of serious camera sales as the market shrinks year over year for the last DECADE. Lens prices are slightly higher for the new Mirrorless vs the DSLR.
But the new glass is VERY good indeed. And while no new 'physics' is involved, new stuff like Low Dispersion glass and High Index glass is being uses as well as Asypherical lenses....Not 'spherical'...... Coatings are improving, too, with Nikon making claims for the Nano coating on some new lenses. Both Canon and Nikon are experimenting with Phase Fresnel lenses. In the case of Nikon, the 300mm f4 PF lens is TINY and has very good performance. With the 1.4 teleconvertor, you end up with a 420mm f5.6 lens which I think the 'birders' will appreciate. If any questions, just find the respective manufacturers 'roadmap'. Canon, for one, has stopped developing NEW lenses for the EOS EF or EFs lensmount. New glass will be for the RF Mirrorless system....