And if read the tasmota compatible devices list, many of the newer china/cheap devices are now being made with wifi chips (no longer esp8266) that can't be flashed with tasmota (yet).
This is for a Feit brand in wall dimmer:
WARNING: New Tuya devices have replaced their Wi-Fi module with one incompatible with Tasmota!!!
Tuya-Convert might not be possible for this device since the template was added (2020-03-12).
IMO they (mfgs) are following the subscription based idea to lock you into their brand.
So after you order 5 or 10 from aliexpress and find you cant flash them, then what?
Tasmota on commercial Wifi devices is hit or miss unless you do your homework.