Wouldn't the argument be that you'd build separate copies of those services as well?

Granted, for banking or government-interactions that isn't feasible, but wouldn't it for many other things? It would likely be more expensive given that the work to build something still needs to be done and the cost is distributed among fewer shoulders and the lower complexity since you don't need to build ad-tech doesn't make up for that, but I suppose that's a bit like quality food.

Hardware will be more difficult.