Why do so many people replace garage doors? Better insulation? That seems silly. Do you hang out in the garage?
Going from a tilt up to a roll up, or segmented door on tracks has two primary benefits;
Door actually seals, top, bottom, and sides, which makes insulation practical. Insulation is good for maybe twenty degrees nicer temperature making the garage more habitable and effects temperature in the house less.
Door opens and closes with a couple inches of clearance. If you park a car in the driveway near the garage door you don't need to move it to open the garage door. More clearance on the inside as well.
Maybe not a big deal for many, but the segmented doors on tracks can be very quiet, such as not disturbing anybody sleeping at night etc.