[baumy]

For large companies there are legal problems there. If you can't give every single candidate the same exact experience / ability to succeed in an interview, you are open to lawsuits. If candidate A got a laptop, but candidate B didn't have the option, B can sue. So if you can't guarantee you will have a laptop at 100% of interviews for a given position, you can't offer it at all.

That said I feel like interviewing is important enough that a large company with (presumably) large resources ought to be able to make sure a laptop is always there. But it isn't as simple as "just bring a laptop", you'd have to have an enforced process.