SmartThings has decent ease-of-use (unless you require accessibility support, which is a separate issue) as long as you have 15 or fewer devices and don’t use any custom code. Which they say is most of their customers. Once you step past that, it becomes a very powerful system, but not necessarily one which is easy to use. And definitely not the most reliable at the present time.
So it really comes down to what your own priorities are. There’s lots of discussion on this in the forum, just search for “reliability.“ here’s a recent discussion:
Classic vs New V3 Android App?
You might also find the following thread interesting, although it can also feel overwhelming, so feel free to skip it if it seems like too much work. 