Yes, I'd agree with that but to me Lambda is much more than that. It's not only suitable for very short running tasks. In fact it is suitable for everything other than very long running tasks. We can build proper APIs and web services on top of lambda and literally only pay for the exact resources we consume. We never have to worry about managing infrastructure, handling auto-scaling, etc. AWS recently also introduced a "serverless" database offering that also comes up when you need it and then goes to sleep. It can scale "infinitely" as well.
I see majority of my workloads implemented on top of Lambda + ECS/Fargate/Kubernestes in near future. Lambda for all short running jobs (1-5mins) like image processing, emails, notifications, web services, APIs, glue code, state machines, etc and ECS for long running tasks like data processing, DB syncs, backups, video encoding etc etc.
I see majority of my workloads implemented on top of Lambda + ECS/Fargate/Kubernestes in near future. Lambda for all short running jobs (1-5mins) like image processing, emails, notifications, web services, APIs, glue code, state machines, etc and ECS for long running tasks like data processing, DB syncs, backups, video encoding etc etc.