We don't even need this story to learn a lesson and be more careful when using our phones. I believe that smartphones have become an indispensable part of our daily lives and many people even value it more than many other things in life. It is not only a tool for entertainment or communication with people but many people also use it to store sensitive information and data so protecting it must almost always be ensured.
This is just a coincidence because even if the thief knew he was a bitcoin investor, I wonder how they could have accessed his phone to get that important data. Since most people have multiple layers of security turned on to protect their phones, I don't think it's easy for someone else to hack into their phones.
I don't know if Android phones are easy to jailbreak but for Apple devices like iPhones the chances of getting into the phone are almost zero without the password. That's why I usually prefer using iPhone over Android phone.