The option to buy devices from different brands is there, but you don't have to. Samsung or Google is happy to sell you a phone, a watch, earphones, and maybe some speakers for your home. Heck, Samsung will even sell you a TV, washing machine, and a fridge if you want.

In any case, what I struggle to understand is the position some have when it comes to install apps on iOS. I understand the security angle, but you can do it right (with Apple always in control of the OS and the permissions apps get), still be in the Apple ecosystem, and having the option to install a VPN app after Apple receives a court order to block said app.

You can buy open hardware running Linux today. Why don't you?

Oh right, the mobile Linux experience is so bad only the most devoted will subject themselves to it.