It does seem absurd that I have to round trip to us-east-1 to turn the lights in the closet on or off but there are reasons behind the cloud-based architecture.
The original SmartThings is a very weak device that can't do a lot of processing on board. Running in the cloud it is straightforward to custom the thing by, say, writing an AWS lambda function. If you had to install "device drivers" for every IoT device on the local device it could be easily overloaded.
As it is SmartThings featureful system that is easy to code for, for instance you can browse a pretty extensive logs in the system that would be hard to store locally. One reason you don't see a good IoT device that runs independently of the cloud is that it would be much more expensive and harder to integrate with.
You might not use it but one of the selling points of the IoT is the ability to remote control devices over the internet and having a bastion in the cloud is the royal road to that being reliable.
The original SmartThings is a very weak device that can't do a lot of processing on board. Running in the cloud it is straightforward to custom the thing by, say, writing an AWS lambda function. If you had to install "device drivers" for every IoT device on the local device it could be easily overloaded.
As it is SmartThings featureful system that is easy to code for, for instance you can browse a pretty extensive logs in the system that would be hard to store locally. One reason you don't see a good IoT device that runs independently of the cloud is that it would be much more expensive and harder to integrate with.
You might not use it but one of the selling points of the IoT is the ability to remote control devices over the internet and having a bastion in the cloud is the royal road to that being reliable.