We've been running on ECS for 6 years now (basically within a few months of GA). When EKS launched we talked about maybe migrating over but ECS just feels more first class wrt cloudformation and stuff. It makes sense that internal teams rely on it.
Literally everything is a Lambda nowadays it seems, so it seems like it's just Lambda -> ECS -> -> -> raw EC2 unless you're building directly on bare metal.
yes! specifically, quite a number of teams use fargate and its one of the 2-3 "obvious" ways to build services.