Ishayu

Because software is constantly reviewed by third parties, you can generally trust that nobody tries to sneak telemetry or spyware into your system.
 
its free - you don't have to activate Windows or pay the Apple tax.
 
its exceptionally scalable. It runs on literally anything. Got a server room and you wanna have 6 users gaming at once? That works. Got a desktop? That works. Got a laptop? It works. Got a phone? It works. You can play DOOM 3 on your $35 Raspberry Pi. The question is never what you can get, the question is what do you want. You can get anything. 
 
 Pretty much no matter what kind of desktop you want, you can have it. Prefer global menu's? We got them. Prefer start menu's? Well we've got' em. We've got both at once!
 
 Game compatibility is great. Lutris doesn't just run Windows games - it runs darn near anything. Got a GameBoy ROM? Check. Got a PSP game? Check. Got a friggin Atari game? No problem. Just about the only thing we can't run is a small set of Windows games because of DRM or anti-cheat as well as anything on dapple platforms. Other than that? We've got you covered.
 
You are in control of your PC. No inconvenient Windows update. No mandatory upgrades. Nothing mandatory at all!
 
 You don't have to scour the web in an insecure way to find common software. No download.com or other such malware laden crap. We've got software in app stores, except everything is free and verified good by many third parties. 
 
to sum it up? Freedom. 

Most of us are not concerned about privacy while browsing a site. Many of us want to give a lot of information to make sites like this one actually work, but we ARE concerned about cross-site tracking, fingerprinting, etc.   I've become really fond of the following combination that's a little less extreme, but still makes it massively difficult to track you.   1) Use Firefox - It's an open browser and, unlike Google and Microsoft, has no interest in tracking you what-so-ever. 2) In Firefox, go to Settings -> Privacy and security -> Content Blocking -> Custom and check tracking, cookies, cryptominers, and fingerprinters. 3) Fingerprinting is particularly important. Many sites ask your browser about all sorts of things that will make it appear unique, and uses that. With this blocknig enabled, Firefox refuses or downright lies about this information, making it impossible to track you this way. 4) While the cookie blocking is nice, it's not enough, because first party cookies are now used to track you. So, install the following extensions:
a) Cookie Autodelete - deletes cookies every time you LEAVE a site. Cookies still work while on it, but as soon as you leave - poof, it's gone.
b) HTTPS everywhere - makes you not send stuff over HTTP when you can help it
c) I don't care about cookies - Prevents the completely useless EU cookies warnings from showing up. Now that you delete cookies, they will ask you every time, ironically. 5) Get KeePass and install Kee for the browser. Kee encrypts all your passwords, which is going to be important since you're going to be logged out every time you leave a site, but crucially it saves the data on your local machine, meaning that no company, such as LastPass, is decrypting your passwords for you. You can encrypt the database with a certificate or password. I recommend a certificate. You can then upload the database, BUT NOT THE CERTIFICATE, to a service like Dropbox or a WebDAV or FTP or similar, because with these you download the entire database each time and decrypt your passwords locally.
6) Use Linux or macOS. Seriously, Windows is FULL of spyware and adware by default. If you're running Windows, you are not safe by definition, period. Microsoft has made sure of that. Apple is much better in this regard, and Linux is the ultimate.
7) Listen to the advice of the Free Software Foundation (or FSF) if you wanna go completely dark. These guys are really, really, REALLY extreme, but they are also completely correct. They're fundamentalists, but also fundamentally correct.

Most of us are not concerned about privacy while browsing a site. Many of us want to give a lot of information to make sites like this one actually work, but we ARE concerned about cross-site tracking, fingerprinting, etc.   I've become really fond of the following combination that's a little less extreme, but still makes it massively difficult to track you.   1) Use Firefox - It's an open browser and, unlike Google and Microsoft, has no interest in tracking you what-so-ever. 2) In Firefox, go to Settings -> Privacy and security -> Content Blocking -> Custom and check tracking, cookies, cryptominers, and fingerprinters. 3) Fingerprinting is particularly important. Many sites ask your browser about all sorts of things that will make it appear unique, and uses that. With this blocknig enabled, Firefox refuses or downright lies about this information, making it impossible to track you this way. 4) While the cookie blocking is nice, it's not enough, because first party cookies are now used to track you. So, install the following extensions:
a) Cookie Autodelete - deletes cookies every time you LEAVE a site. Cookies still work while on it, but as soon as you leave - poof, it's gone.
b) HTTPS everywhere - makes you not send stuff over HTTP when you can help it
c) I don't care about cookies - Prevents the completely useless EU cookies warnings from showing up. Now that you delete cookies, they will ask you every time, ironically. 5) Get KeePass and install Kee for the browser. Kee encrypts all your passwords, which is going to be important since you're going to be logged out every time you leave a site, but crucially it saves the data on your local machine, meaning that no company, such as LastPass, is decrypting your passwords for you. You can encrypt the database with a certificate or password. I recommend a certificate. You can then upload the database, BUT NOT THE CERTIFICATE, to a service like Dropbox or a WebDAV or FTP or similar, because with these you download the entire database each time and decrypt your passwords locally.
6) Use Linux or macOS. Seriously, Windows is FULL of spyware and adware by default. If you're running Windows, you are not safe by definition, period. Microsoft has made sure of that. Apple is much better in this regard, and Linux is the ultimate.
7) Listen to the advice of the Free Software Foundation (or FSF) if you wanna go completely dark. These guys are really, really, REALLY extreme, but they are also completely correct. They're fundamentalists, but also fundamentally correct.