What is the best Gamelift setup for running persistent worlds?

We’re curious about using Gamelift to run something like Ark Survival, shards of persistent worlds of up to about 100 concurrent players.

Is using Gamelift a bad idea here? I ask because Gamelift’s strength is its ability to scale up and scale down new instances (servers) to support session-based games, but I can’t see if/how this strength translates to persistent worlds. As a persistent world always needs to be there, each shard will require one server to be running it at all times, at the very least, correct? It doesn’t seem like any scaling down could occur here, which would be overly expensive, correct? Is there a decent cost-effective way to use Gamelift with persistent worlds?

OK, found an answer here:

https://forums.awsgametech.com/t/is-gamelift-only-good-for-session-based-games/2510/1

EC2 and RCS are preferable.