In the real world you'll always only ever see the duopoly of Android / iOS for phones for example. This can be government apps, parking apps, apps for your utilities etc. so it's not like there's an easy choice to opt-out of that. It's not much different for laptops (Will still have some non-free blob in them for some driver), TVs, kitchen appliances.
There is no escape from duopoly if you need banks for 24/7 - get rid of that need now or the slippery slope of the technofeudalist slavery will suck you all even deeper into never wanted outcomes.
For example, there is literally no laptop on Earth as nice as the MacBook Pro. Extremely long battery life, insane CPU & GPU performance, unmatched trackpad - but it runs MacOS. Unless you're a professional video editor, the laptop is largely relegated to being a thin client for a Linux machine you SSH into (or spawn a non hardware accelerated VM and demolish performance / power).
How long would it take Apple to develop Linux drivers (even as binary blobs like nvidia)? Probably a couple of weekends. Why don't they? Because walled garden.
The MacBook is lucky in that it's a high profile device so we see projects like Asahi working at it - but again, without good documentation and despite the incredible progress, the Asahi team have spent years and created an alternative for older Apple hardware that still isn't daily drivable (not throwing shade at the project, it's incredible and I am dying to use Linux on my MacBook).
But what about devices with less enthusiastic communities? Pixel 8? Samsung TV? Asus Router? Fitbit Air? D-Link portable 5g modem? My smart blinds?
These devices have no drivers, locked bootloaders, and no community to spend years reverse engineering hardware (that will be obsolete by the time OSS drivers are developed).
I want to see my high end consumer hardware running OSS and until regulators step in to force the "right to repair software" - I don't see that happening and it breaks my heart.