The problem of course is that Fi is U.S. based which brings a few extra headaches with it for people who want the service but are based overseas, or for expats living abroad for a long period of time.
Note: I also have some Voip apps on my phone giving me a few different phone numbers to the same phone without the SIM/eSIM mess. But these days I'm finding I'm more or less just making voice calls over apps anyways meaning I'm using voice service less and less.