The ground effect was the majority of the visibility issue. The whole point of the regs was to reduce dirty air by having the floor generate the majority of the downforce, then throwing it up vertically by the diffuser to prevent it causing turbulence behind. But this also led to water being sprayed the same way during wet conditions, leading to those huge rooster tails that destroyed visibility.

Theoretically the new regs should be better. Maybe not completely fixed, but it should be better.