Most companies just don't have a reason to look through the computer they're letting you use to do your job. Don't give them a reason.

Maximizing shareholder value by observing you doing job in the pursuit of replacing you with a very small shell script is a great reason that they've just discovered.

Get your own laptop, pay for your own cellphone, use your own internet service, etc. If you create anything of value on their property or with their property or during times they're paying you in any capacity, expect them to use it for profit.

Exactly, no one is stopping one from using their personal devices for any personal purpose, and the fact that somehow people are defending wanting to do personal things on a work laptop is utterly baffling to me. Like another commenter said, I always grew up with the notion, legal and social, that a company laptop is absolutely not your property and companies can and will look through it. Use your own devices for your own tasks.