ECS Fargate. We used it for a lot of stateless containers, similar as you mention.
I tried to migrate from ECS Fargate onto EKS, but moved back after a while. The reason was the "management" overhead of babysitting the cluster and it's non-app deployment like cilium, fluxcd etc. - Since those were part needed and part QoL features we came to the conclusion that ECS Fargate was the better and less 'head ache' solution. I would do it again. Especially not thinking about provision new nodes etc.
Sure you pay for that comfortable solution, but it was worth in my opinion
Sure you pay for that comfortable solution, but it was worth in my opinion