I bought Xperia 10 III a week ago. I have witnessed the same thing. Grass is not always greener on the other side. Android’s telephone/calling app crashed two times (2!) before I got to make the first call. I thought this is an ability that only SFOS can 
I was terribly wrong 
And it goes on;
Connecting the phone with Android Auto to my car, makes the whole phone reboot sometimes when searching for an address to navigate to.
The only thing that bugs me quite alot with the switch to SFOS is that I loose connectivity to my camera (Fujifilm) …but you need to give something to gain something I guess 