Youtuber loses PSN account due to hacking, Sony refuses to do anything

This is indeed a problem in our digital age, our dependency on online accounts for which no support is available at all. One could say, for instance, that if someone was to lose his Gmail account, he would lose his whole life and would be ruined. If he attempted to call Google about it, there would be no human to help him with anything. The fact that there are either dozens or hundreds of millions of accounts for a service makes it impossible for customer service to service and value all of those accounts.

But likewise, customer service can be your foe as well. The reason why so many of these accounts are getting hacked, is because the customer service reps allow it. It has happened for a long time: people calling Sony or Microsoft to "reset the password for their online account", who are really people who want to take control of another account. It happens either for vanity reasons (people with prominent handles in the online gaming community), or because it's people from foreign countries who want to quickly monetize the accounts by re-selling content. In essence, your account is as secure as the most careless and apathetic CS representative working for these companies.

That's why I never share my PSN account handle with anybody and never play online games, I only use it for buying stuff on sale to then play in single player.

It's "take money from customers and forget them afterwise" aka "hit & run", cynically speaking.