Is it ok to tile over skimmed plasterboard?

My bathroom walls are plasterboard which are skimmed and painted.

Is it ok to tile on top of this? and if i do will I run the risk of the tiles falling off in a few years?
I'm considering pulling down all the plasterboard and putting up good quality plywood in its place to tile on. Is this the best thing to do?

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).