I made the transition from S10+ to iPhone 12 mini earlier this year and I haven't looked back (my last iPhone was the iPhone 6). With regards to software; everything works without fail on the iPhone in my experience and the OS is slick and smooth. I also bought myself a Macbook Air just before I got the iPhone and integration between the two is fantastic. When I'm due an upgrade, I'll be sticking with Apple.
edit: the only negative I've found is that I was a big user or Google Photos and although that works on iPhone, the photos I had prior to the iPhone 12 were all on Google Photos. Any new photos are on Google photos and the Apple photos app. I guess I could just use Google Photos but again, the fact that the Apple photos app syncs with the MBA without any faffing around means I'm happy to use two (and pay for two cloud storage options).