I see it like this :

Once there were a lot of free tera byte image hosting services. And then after some market ups and downs, most of them either closed down, asked for subscription fee or hugely restricted what can be done.

Free static hosting services might not remain such for long. At the very least, they might introduce terms or condition you might not like. Then it will be harder for you to shift to another service, compared to switching your VPS server.

Also I count my time spent on managing the servers as free. For me it's experimenting what else can be done, gaining experience and overall enjoyable time spent.

That might not be true for everyone.