Ya. But if neutral available it will be easier to install.
In the socket. Target is to install in all bedroom and living room.

With smart switch, we can use alexa or google home to control the home appliances using voice or smartphone.
Yes. But it will be easier to install if neutral is readily available.

Not that hard to install without neutral. Just extra 1 step to install capacitor at 1 of the light. It might be even harder to install with neutral especially those 3 or 4 gangs because so many wires with so little space to cram all the wires in. Trust me, I had install more than 20 wall switches.