The opposite happened. I'm more focused on the road since I can relax and not multi-task. On long road trips, I'm not feeling that ache in the knee or the tension in the shoulders/back from constantly keeping the car aligned in the lane. In fact, I wish Tesla would just introduce a touch interface into the wheel so it knew your hands were on it, but not require constantly resisting the wheel to trigger the sensor.
The conclusion I've come to: Level 2 can make good drivers safer and make bad drivers more dangerous. I don't look at my phone when I'm driving. I don't text at red lights. I don't constantly fiddle with the screen. If you do these things, you're a dangerous driver. If Level 2 increases this because you feel a false sense of safety, it'll make you more dangerous.
People just need to take driving a 2 ton heap of metal 70mph seriously and we'd all be much safer.