It is important to know the distinction between 3 similar features that do slightly different things:
Lane Keep Assist (LKAS) - helps steer you away from the edge of the lane when you drift near the edge of the lane
Lane Centering Assist - a higher level of LKAS that keeps your car centered in the lane
Lane Departure Warning (LDW) - warns you with beeps and/or vibrations when you're about to veer out of the lane
I am pretty sure the 2020 Accord and 2020 Mazda 6 have LKAS and LDW. The degree of effectiveness may be different though. Also keep in mind these systems may have different threshold speeds below which they do not work, and they will stop operating and warn you if you take your hands off the wheel for too long.
Lane Keep Assist (LKAS) - helps steer you away from the edge of the lane when you drift near the edge of the lane
Lane Centering Assist - a higher level of LKAS that keeps your car centered in the lane
Lane Departure Warning (LDW) - warns you with beeps and/or vibrations when you're about to veer out of the lane
I am pretty sure the 2020 Accord and 2020 Mazda 6 have LKAS and LDW. The degree of effectiveness may be different though. Also keep in mind these systems may have different threshold speeds below which they do not work, and they will stop operating and warn you if you take your hands off the wheel for too long.