A live oak or a laurel oak left alone will hold branches out sideways at head height, and on a small lot those are the branches that end up over the driveway, across the walk to the front door, or in the way of the mower. Lifting takes those off at the trunk or at a main limb, so the tree keeps its shape and you get the ground back.
Clearance is worth thinking of as a height rather than as a feeling that the tree is in the way. General practice is to keep a walkway clear to roughly eight feet, which is above the height of anybody using it, and to keep a driveway clear to something nearer fourteen feet, because a pickup, a van, a boat on a trailer or a delivery truck all need more room than a car does. A limb that a sedan passes under all year is the one that takes the corner off a moving truck.
Lifting is done in stages over more than one year on a young tree. There is a limit to how much live foliage a tree can lose at once and still feed itself, and the general rule is to keep it to about a quarter of the live crown in a single year. A tree stripped bare up the trunk in one go loses more leaf than it can spare, and it answers with a rash of weak shoots along the trunk.