smartthings chose the cloud for “scalability”.
– I expect they saw the problems vera and other systems had with provisioning enough local resources, and this drove their decision to do more in the cloud. (the vera problem was not enough memory, etc to run many automations)
… However using the cloud comes with its own set of scalability challenges, which we are all living with now. These are resulting many times in a non-functioning system.
As other threads describe, more local processing needs to be (open question is there enough resources to do much more local processing…) done.