What worries me in Sailfish is that AFAIK the OS is not fully open-source

My four biggest gripes with UBPorts - namely the lack of Swype-like keyboard, crappy native Signal and crappy Waydroid / Android Signal integration, the swipe-right thing in the UI that drives me up the wall, and the battery status hidden behind the in-screen camera - are supposedly solved by the Jolla phone.

I too am a bit concerned about the future of the company, but here’s my thinking:

• If the Jolla delivers, then I’ll have a phone that I can daily-drive. There’s precious little choice if you want a Linux phone, and even less choice if you want a good one. So… It’s not like I have much of a choice.
• I would very much prefer it if SailfishOS ran on a Fairphone. Apparently there’s an ongoing project to port SailfishOS but it’s not quite there yet. So I’ll buy the Jolla phone for now, and if/when the Fairphone5 port of SailfishOS is mature and usable, I’ll resell the Jolla phone.
• I have the disposable to buy a new phone and a SailfishOS software license. I’d rather not do that, but I’m old enough and the kids are out of the house that it’s not a strain on my finances. Hell, I have FP5 loaded with UBPorts right here that’s sitting unused on a shelf…
• I’ll take my chances on Jolla-the-company. At some point, someone has to pony up the money and support Linux phone makers if we want Linux phone makers. If nobody pays up for fear that they’ll disappear, then it’ll be a self-fulfilling prophecy and they’ll disappear. So let’s say I’m doing my part to support a commercial non-Android outfit.
• If SailfishOS is not fully open-source but Jolla doesn’t violate any of the open-source software packages’ licenses, then so be it. Android isn’t fully open-source either - far, FAR from it, even deGoogled AOSP variants: they all rely on proprietary kernel blobs if nothing else. So it’s not really any worse.