I know you can drive to Glacier Point, and if you have mobility challenges you should absolutely drive and experience the incredible views of Half Dome. But if you can, you should definitely hike up from the valley. There’s the obvious, the added value of a view when you’ve actually put in the physical work to get there, but the hike is worth it in itself. When you get to Glacier Point you’ll be sharing the view with the incredible volume of people who drove up, but the entire trail is open views of Half Dome and the entire valley that you’ll have virtually to yourself. There are plenty of lookouts to stop at as well, and if you’re willing to hike in the dark the trail looks out to the west where you can get a stunning sunset over the valley.