I do not think it is a dead end yet. The barrier to entry has to do more with hardware compatibility and access to device platforms that are not completely locked down with proprietary bullshit.

There is substantial work being done to make it happen. Unfortunately this is a slow moving progress.

Unless more manufacturers find value in it, or open source projects make more of their own devices. We will always be trailing behind.

Unfortunately true, Linux phones are still completely unusable.