If there's fewer kids born today, there's a likelihood of fewer coders in 20 years.
At a smaller scale, I love Heroku for prototype apps, and I would absolutely use them for a startup - right up to the point where I'd be paying the equivalent of 1-2 full-time devops engineers. At that point, it becomes worth it to hire them and transition away. AWS has a similar value proposition, but the tipping point is higher; I'd estimate it at around 15-20 FTEs in Amazon charges before it starts to make sense to leave.
Rolling your own infrastructure is in a lot of ways def easier than rolling your own programming stack today.