Unless you're renting from multiple $10/month services, your service can be only as reliable as your service provider, which is probably less than AWS.
You hit it on the head. Weave Net is participating in the Istio project. I hope they can bring WeaveNet to Istio. That might be able to provide a multi cloud vendor service mesh.
But that’s easily possible – you can use all the French hosters at once. Latency between them is practically nil because their data centers are only a few hundred meters away from each other.
Sure, in case all of Paris goes down, you’re down, too. But in day-to-day usage you can have good reliability on a shoestring budget.