I am not saying make a 24-100 F2.8 with all metal construction.That is what I and many others want.
Small and light has to be slow and with plastic.
Many L lenses are plastic in a lot of the lens.
I personally am very happy with the new lenses as I am planning on getting the new M camera if it is an M5 replacement.
That is what has me holding off.
If I want big and heavy I will stick with my L lenses and the 7D or get an R with big fast lenses. But this is great for a second handy camera.
Plastic build is fine if good quality plastic and at least a metal mount.
The Fuji 18-55 2.8-F4 is 309g and very good build and image quality.
The Sony 16-70 F4 is 307g.
Neither is very expensive or heavy. Something like those 2 lenses could Canon build.
Not kit lenses with plastic mounts and F6.3 aperture.