I walk my dogs once or twice a week here lately, because of a few issues (i do like to walk them though).... Murphy almost never gets walked, it would mean a separate walk just for her because she can't go very far, and she's not *my* dog (i have my own to exercise), but every once in a while we go for a slow meander around the block.
BUT
I spend at least an hour a day (usually more, broken into two sessions or so) just playing fetch or frisbee with the dogs... so a lot of constant running, which IMO is better than a sedate walk. In addition, Popper and Merlin are working on agility in the backyard (doesn't count towards that hour of play), which we do at least three times a week, and Popper has agility class as well once a week. We do flyball inside our house once a week for everybody but Murphy (and flyball definitely is a lot of exercise!). Sometimes we go to a dog park (just the boys) but not terribly often because it's a good 12 miles away.
I used to go over to my parents' house because they have a nice big backyard (and doggie friends) and that was always great exercise for them to run around like idiots for a couple hours, but I'm still waiting on their neighbors to put that promised fence up.
I used to do that at least twice a week and it was awesome. Stupid neighbors.
Right now I've got my doors all open and every ten minutes the dogs see a squirrel, race through the house, out the backdoor and zoom around the yard trying to get the pesky thing. That's some nice natural exercise too LOL. At least they aren't cooped up in a house all day.
Ideally I'd love to have 50 acres of land and just walk around with my dogs nipping at my heels.. just not doable right now. To walk them is an ordeal, with all the loose dogs or dogs tied out in their front yards. And people always want to stop and talk to me about the dogs, which gives them an opportunity to run around my legs and get everyone tangled. Money for gas is an issue as well, otherwise I could drive them all somewhere... but there would still be other dogs, and Roofus in particular gets VERY excited at the prospect of a new friend!
I don't feel like my dogs don't get enough exercise. I feel, unless your dog is a working dog, they could always have MORE!
ETA my dogs don't lack socialization
we go to the pet store (one or two at a time), and my boys went to doggie daycare for the longest time. Plus I have a tendency to take at least one dog with me nearly everywhere I go.... Roofus is the friendliest dog you'll ever meet.