Linux on Mobile and open EC and Coreboot etc. are all making rapid progress at the moment. I would still say we are talking in terms of years before more general Linux Phone adoption would be possible, and still the fact your online bank etc. doesn't make an app for Linux would be prohibitive to many (although anbox might help), so I understand pessimism here, but I think the excitement around Linux mobile and open hardware is sufficient that it will at least be revolutionary that it is possible to run open hardware and Linux phones etc. same as SteamOS was a failure if you look only at numbers of Steam Machines, and a revolution in Linux gaming if you look at Proton, GamerOS and all the improvements that came with it.

Viable alternatives affect the behavior of others, even if they "fail".

And if you're already a desktop Linux user like me, open hardware is already a reality. Only thing that's stopped me trading Dell XPS 13 for Purism 14 is that I will miss the QHD+ screen, as it is standard HD res. Still really tempted though.