Scaling is a hard problem. I've worked at places where we used a whole network of auto-scaleable services and guess what - you will still have problems. Each managed service has tradeoffs, often ones that you only encounter once you'd made a substantial commitment to that service. There is no free lunch and you're fooling yourself if you think there is one.
Often you get lucky and the cluster of managed services you select happen to scale along the metrics of your resource use. Many people's resource use patterns are similar and the managed service people take advantage of that. This is nice! But it's a trade for downside risk: you may find that your resource use patterns differ from the 90% case and your spend goes up very fast or your scaling hits a wall.
In my experience a lot of designing a service architecture is picking where you want your complexity. Services (in or out of containers) running on VMs have a simple billing and architectural model. In my experience they form a good basis to organize your other resources around and are a good foundation to grow from.
Often you get lucky and the cluster of managed services you select happen to scale along the metrics of your resource use. Many people's resource use patterns are similar and the managed service people take advantage of that. This is nice! But it's a trade for downside risk: you may find that your resource use patterns differ from the 90% case and your spend goes up very fast or your scaling hits a wall.
In my experience a lot of designing a service architecture is picking where you want your complexity. Services (in or out of containers) running on VMs have a simple billing and architectural model. In my experience they form a good basis to organize your other resources around and are a good foundation to grow from.