Non ping-ponging lane following assist is already available in many cars including KIA and Hyundai models. They're very conservative and disengage very easily. I think it's by design to minimise their legal accountability
Not just legal accountability, but actual safety. They are designed so that they do not give the user a false impression of the extent of their capabilities.
I've been incredibly surprised to see that lane assist in my Kia is significantly better than that of most other (legacy non-hi-tech, think nicer hondas and lexus ICE/hybrid) cars I get a chance to drive.
I unfortunately don't have radar cruise control on my Kia, though, which would make highway driving even in traffic completely effortless, and this seems to be standard on themore expensive cars. Maybe it's for the better, though, because it does force me to be much more attentive on the road.
Hyundai actually has two systems, LKA and LFA. LKA just tries to bounce the car back when it detects lane edges, LFA actively keeps the car in the middle of a lane.
All Hyundai models in Europe have LKA, some (more expensive) also have LFS.
