Nope, most smart switches can be powered by a capacitor connected between live and neutral at the light.
My home is full of them as I run 'Google Home' voice commands to control almost everything.
No need to think, the switches come with the capacitor.
https://www.lazada.co.th/products/smatrul-wifi-tuya-app-alexa-google-home-123-gang-i3783968316-s14384376219.html