  _____ _               _               _____ ____  
 / ____| |             | |             | ____|___ \ 
| (___ | |__   __ _  __| | _____      _| |__   __) |
 \___ \| '_ \ / _` |/ _` |/ _ \ \ /\ / /___ \ |__ < 
 ____) | | | | (_| | (_| | (_) \ V  V / ___) |___) |
|_____/|_| |_|\__,_|\__,_|\___/ \_/\_/ |____/|____/

FAQ: Why should I care?

First of all, take a look at this Wikipedia page, especially the section on arguments for privacy. That explains why the "I have nothing to hide" argument is, frankly, ridiculous.

Wikipedia page for "Nothing to hide argument" The "arguments for privacy" section of the same page

Now, to summarize the situation: large tech companies like Google, Microsoft, Facebook, Apple, and so on, have incredible access to large amounts of information about us. If you doubt that, look at

Your Google location history An archive of all of your Google data

The information contained in all of your emails stored on Gmail, Outlook, etc.
All of the other information you've shared with social media platforms: your phone number, address, pictures of yourself, a record of your day-to-day activities...

Google scans all of your emails and everything else you put on their platform to serve you targeted ads 96% of Google's revenue came from advertising in 2011

If you really don't care that they know so much about you, then go ahead and continue using those services. Really, go on. It's your choice. If the idea of a company knowing so much about you and monetizing that knowledge is concerning, you might want to try the No GApps initiative for yourself. If you look for them, there are better, more privacy-friendly alternatives to every service you use.