100-400 and what else?

My old Panasonic 100-400 is very stiff, like it's always been. And current lenses sold are just as stiff, as they have not fixed that. And the Olympus is somewhat better, but still not easy to turn like the 40-150 2.8

I'll assume that there is a solution? Am I wrong? Any other lenses that are smooth?

Mu Canon EF 100-400 II has a ring allowing to control that stiffness. In my bag, it is set to max; when I shoot, I turn it to min.

Most any competent repair technician ought to be able to adjust tension on most any zoom or focus ring.