What's least inconvenient depends dramatically on context. For example, I've lived in and more-or-less near New York City at various times. Living in the city, I didn't bother owning a car. Too much traffic! And impossibly expensive parking, unless I wanted to commute to my car ;) Whenever I actually had to drive somewhere, I just borrowed or rented a car.
Within the city, I almost always used subways. That was mostly back in the day when they were very grungy. And they're still horribly noisy, compared to those in Toronto, Moscow, London, etc. Or even Chicago ;)
Sometimes I lived near the city, with easy access to light rail. So I used that, because it was much less hassle, and less expensive, than driving. There is always the risk of missing the last train, of course. But hey, stuff happens ;)
When I lived near the city, with no easy access to light rail, I tended to commute to the train station. If there was one closer than the city, anyway. That was still less hassle than driving.
But when I've lived way out in the suburbs, driving was often the only option. As others have noted, public transit just doesn't work for suburbs. People and their destinations are way too scattered. So there must be multiple transfers, and long waits.
Maybe one of the "pods on tracks" designs will work out. Or maybe people will just move back to cities.
If you drive everywhere, and everywhere you go has convenient parking, that'll be the case.
I find that often the best my car can offer is to take me from where I might be (home) to somewhere in the general area I want to go (where I have to pay for parking, if I can even find it), marginally faster than the bus and often slower than BART (unless traffic is clear). If I've walked to any of the many attractive destinations within 20 minutes of my apartment, it's then substantially faster to get on the bus at any of several nearby stops than to return home to get my car. (Generally, the need to return to where I parked is something that I find quite inconvenient in situations where interesting destinations are dense.)
I live in Oakland and currently work in SF; I grew up in Santa Cruz, and spent years in Ann Arbor. In all these places, I found many trips more convenient by public transit than by car (in no case was that all; currently it's close). I certainly recognize there are places where public transit is even worse, and even in these places there are people for whom it works out less.
> My car takes me from right where I am, to exactly where I want to go, exactly when I want it to, in a minimum of time.
There are ups and downs to both options. With public transit, someone else drives and you can get work done (or nap or whatever else you wnat to do), so the time cost arguably is less.
Personally its not the slowness that I mind so much. I spent a week in Japan and was never bothered by their train system times and whatnot.
The thing that really grinds my gears about BART is that every freaking time in their time table is +/- 5 minutes. I can't plan any sort of schedule around it to save my life, and thus I personally feel that I waste a ton of time waiting around for the next train. I never felt that in Japan. Every transfer and connection was exactly on time and there were plenty of trains where I was never sitting around waiting 20 minutes because I just missed the BART.
My car takes me from right where I am, to exactly where I want to go, exactly when I want it to, in a minimum of time.
Public transportation takes me from sort of where I am, to the general area I want to go, slowly, on their schedule and not mine.