I used to be pretty good at driving when I was doing it regularly. Now that I’ve had access to public transit for years, I have gotten much worse at driving.*
A few times a year, it would be helpful for me to drive. So about once a month, I practice driving somewhere. But once a month is not often enough to get very good.
So if Jeff and I are driving someplace, is it safer if I practice driving (so that I get better at driving overall, even though that individual trip is more dangerous than if Jeff were driving?) Or is it better to reduce the number of trips I drive, hoping that three less-skilled trips a year are safer than 20 medium-skilled trips?
*I’ve still never had a car accident, so I’m basing this on the frequency of Jeff saying things like, “That was a stop sign!”
The whole sky 
My own approach is to avoid practicing as a sort of pre-commitment to driving less. This actually has kept me from driving in some marginal cases, mostly by giving me a good excuse to throw at social pressure. (“I don’t want to drive for these complicated reasons” doesn’t go over as well as “I would be a danger to myself and others.”)