This. "Choice is good" says the man himself. Y'all know my feelings on this subject quite well by now. I know people like to try to do it all with a single system, but that's just not for me. I don't like instability (who does?), but that's just not my experience with what I've built. If you're new, there will be growing pains, but the fruit of being able to decide what you want to add, instead of constantly needing to ask "Can I add it?" is very sweet. Don't get me wrong, there are still limits to what I can add to my setup, but I don't have many.
Bruce has built one heck of a good automation application, and yeah it's damn powerful given how easy it is to use. I don't really believe that HA automations cannot be made to do everything that I can do with Rule Machine, but the YAML needed to get there is something I'll never touch. Their basic automations are fine, and have become pretty easy to setup in the most recent version of HA, but to me they make little sense (except in very specific situations) when HE Rule Machine and Basic Rules cover what I need with very little effort.
I am intrigued by Homey's Flows since they look so much like Stingify, which I really liked (except for the cloud-based part), and they're also local. Problem there is, that hub is just ridiculously overpriced for what they can integrate with today. They need to give their head a shake or they are just not going to survive. If a competetor was to create a similar graphical automation engine on a reasonablly priced hub, they'd be unable to compete at that price. And no, all you NodeRED fans, it's not directly compareable.
Getting back to Hubitat, I have considerable faith in their backups. They work, really well. This is another reason I trust all my automations on my Hubitat hub. Easy or not, it's not a trivial task to set all those automations up over time, so you better have a backup of them you can be certain is reliable. Yes, there's a backup in HA, and I can backup to google drive for free, but I haven't needed it yet, and I've never tried it. Only backup I have restored is the entire microSD in my RPi. That of course works, but it's more difficult and slow to do. Hubitat is fast and easy to do, and I have been saved by it several times (some by my fault, some not).