Every third party entry point allowed opens the door to more opportunities to breach your system. Google and Apple and my internet carrier really have no business in my home security system.  They often get hacked. 

True but how often am I going to use it now that arming is automatic every night or I can use the app if I'm out and forget to arm it?

HomeKit seriously sucks. Whoever designed it was a madman. I use the new automatic feature on SimpliSafe instead. Arms and disarms itself every night and every morning automatically at the preset times. Never have to worry about forgetting to shut i