Looks like SmartThings is finally getting a new rules platform that will compatible with the new app.
Of particular interest is this statement:
Samsung is also adding local execution support “soon,” the company says. That will trim latency, so that rules act more snappily. It’ll also mean independence from your internet connection, so that even if your cable or DSL is down, your rules will still run as expected. That could’ve come in useful when SmartThings downtime last year took the whole system offline.
If they're able to get local execution finally, that will seriously undercut hubitat. The versatility of ST cloud integrations combined with local control for Zigbee and Z-wave? That's gonna be very hard to beat if they can get it working.
With those specs it ought to be possible! If written in a compiled language rather than interpreted it would be super easy.
A remake of a PlayStation game I helped write 21 years ago has just come out. We had 33Mhz and 2MB of RAM to work with back then. Writing in C you can do a hell of a lot with that- way more than a rules engine!
I just leapt from SmartThings, and am no novice. Been in HA for decades, was a published author in six issues of PHA, wrote a very popular HomeSeer plug-in years ago, and LANNouncer for SmartThings. Just sayin' I know my way around.
IMHO, the biggest problem with SmartThings is not the cloud. It's the lack of any customer focus. In addition to their instabilities, some of which were cloud based, they have the constant stream of bugs, the lack of any usable support, the developer-antagonistic processes.
And, when you think of the bugs and blame "the cloud", realize that they'll have the same bugs locally. Writing cloud-based code is generally easier than client code, because you can control more of the variables.
Keep in mind that Elevation was trademarked by Hubitat less than two years ago. SmartThings is over six years old, more than three times as old as Elevation. If they've still got so many fundamental reliability issues... it ain't gonna get better by spreading them out onto local hubs.