Leasing only makes sense in a business scenario if your business is one that needs to care about the appearance of its balance sheet (because the lease obligation doesn't show as a liability, nor does it deplete your assets).
But if you have more than enough cash for your needs, IMO you are always better to just buy the damn thing rather than lease. Leasing companies make money, and guess where they make money from -- you! If you choose not to do business with them, the money they would have made stays in your pocket.
Yes, businesses can claim the lease as a deduction. But so they can with depreciation.
Yes, you can invest the money you'd otherwise spend on some brilliant fool-proof investment scheme and double your money, but that falls under the heading of not have enough cash for your purposes.
Leasing is a good way to hide something on a balance sheet. Other than that, it's best thought of as a more complicated loan (you them owe money, and you even owe them the car back at the end). Lease companies are not humanitarian organisations - they profit from the difference between what it costs and what you pay. You have the option to not be involved.