As @[email protected] said (https://lemmy.ml/comment/3459977), I believe they have different use cases. The TL;DR is: syncthing to have the same copy of a file across different devices, LocalSend to move files between devices directly.
On syncthing you have to upload the file to the synced folder and then download the file to your device, so like device A -> server -> device B
.
Whereas on LocalSend you send the file directly between the devices, like device A -> device B
.
It’s really good to see this spreading to more manufacturers (although I’m not sure if this will also apply to their lower range devices). Especially because even though your OS updates may be capped at 4 years, you will still receive app updates for 2+ more years, including system apps. As opposed to iOS, where your system apps stop at your last update and developers bump minimum OS versions quite quickly.