I do both.
My yorkies we free feed. We have the bowls down all the time but we only fill it up once every night. This way they can still eat when they want but they aren't going to be over eating as that is all they get. When I first started it they would pig it down. Now they have learned and will eat their portion on and off during the day. I have a few tiny ones so I feel more comfortable knowing that there is food available for them at all times.
Now my two big dogs of course I only do schedule feedings as they would never stop eating if it was up to them.
There are advantages to both.
When you do scheduled feedings they do have a more regular bathroom routine and you can monitor their weight more closely this way.
For me free feeding has the bigger advantage as my little ones need to eat several small meals a day and this way I don't have to worry about them as much. I also had some problems with poop eating when I was doing scheduled feedings. Ever since we did the free feeding that habit has completely stopped. And since they all go on pads the bathroom routine isn't a big deal other than having to change the pad a few more times which I don't mind.
You just do what works best for your dog and your situation. For some it is free feeding, others it is scheduled feeding. As long as your dog is satisfied and at a healthy weight you're doing the right thing.