I mean, kinda.
I was just thinking about this on my drive in to work this morning. I was doing the brakes on my dad's CLS550 so I was driving that, and compared to my Mustang, I really don't need to do very much. It's very easy to start to rely on those safety/convenience features like lane assist, adaptive cruise control, blind spot check, etc.
So are they making us worse drivers in the cars equipped with these features? No.
But if you took a person that's only driven, say, newer Mercedes with all those safety features, and put them in my Mustang, I doubt they'd last a week with no traction control, a heavy clutch, disabled ABS, no blind spot check, etc.
So as long as nothing fails, and these people keep doing what they're doing, it's probably fine when you look at it by the numbers, but when you come down to actual driving skills, it makes them way worse.