Way back when Firefox was Netscape,the same thing happened.
Good thing we have the choice to turn our backs to those "big market players", isn't it?
Yup..Sixteen year Linux user here with FF as my browser and Netscap0e as my browser way back when.
Android users are also using Linux,as are smart tv users,they just don't know it.
About Android and smart tv's: it's the Linux kernel that is used for those devices and probably a very modified one also. The rest of the software that comes with those devices is mostly proprietary. But you're right about people not knowing about it and eventhough people would know, most people do not care about it. Not because they do not care about safety or functionality, it's because they want their equipment to just work without any technical knowledge from their part. Which is a bit sad, but understandable.
The big corporations that bring their devices to market want to sell and make profit, regardless of users' privacy or safety. In a neoliberal and cancerous economic context that's also sad and understandable. But is it something consumers should agree to? I think not, but again, do most people even care? Concious apathy is an illness lots of people will regret in the long run.