replace their watches,
Never really got the craze around smart watches.
their TV streaming device
if your streaming device requires you to have a certain type of phone to use, you should replace it regardless. Roku/AndroidTV/etc... They don't care WHAT type of device you try to stream media from. Have an IPhone? Sure. Android? No problem. Blackberry? That might not work.
their car chargers
Wait until you realize any 5$ charging cord from the corner store can charge your phone, and connect it to your car!
all their apps
Most of those work just fine on android. Just swapped my Dad's phone from apple to android a few months ago, and was able to find all of his apps without any issues.