Tuya Smart and Smartlife are the same company just different versions of the app like smartthings and smartthings classic.
Geeni Smarthome and Merkury Innovations are the same company Geeni is just a brand name of Mercury but they are not with Tuya. Tuya just does the devices and software for them.
Im pretty sure tuya makes the software and hardware to the company’s specifications.
https://en.tuya.com/