Samsung has discontinued many products as well, some only a few years after release, including the SmartThings Thingshield, the ST motion sensor that could run on USB power, SmartThings Connect Home, the ST Nvidia Shield, the ST arrival sensor, the ST/ADT dual logo hub and all the dual logo accessories, etc. and several of these had no comparable replacements.
My own guess is that the SmartTag will be discontinued within a year because technically it just doesn’t compete with the AirTags: but the recently announced Galaxy Smart Tag Plus will be the recommended replacement.
Most technology companies do something similar either because market demands change or technology changes. It’s a rapidly evolving industry.
So I would gladly bet you a virtual beer that in this particular case the Samsung SmartTag will be discontinued before the Apple AirTag, because Samsung just announced the replacement this month. 
