> Ubuntu Touch is still going, fairly strong too, though I think it's aim is to fill a niche rather than challenge Android and iOS anytime soon.

Do you consider getting no major OEM adoption in 5 years “fairly strong?” Mobile OSes depend on network effects of both users and developers. It’s no surprise it’s a duopoly.

In the world of Linux, 'no major OEM adoption' is the norm for most distros especially with no substantial corporate backing. UBports is definitely in the top 5, if not top 3, of (free/libre) mobile Linux distros. So yes, for people who are into the non-corporate Linux distros, UBports is going strong. But all that really means is actively maintained and has a reasonable (by open source standards) number of users.

Debian is still going strong after > 20 years with no major OEM adoption (except in the form of derivatives like Ubuntu), so I'm not sure how relevant OEM adoption is to FLOSS distributions.

Personally I think OEMs should not ship a default OS and should require a choice at the point of sale.

>Do you consider getting no major OEM adoption in 5 years “fairly strong?”

'No major OEM adoption' is partly the USP for manufacturers like Pine Phone[1], if they are able to build sustainable business then they would be fine(From the looks of it, it seem they know what they are doing).

[1]https://store.pine64.org/

Pine is not a major OEM. Even if they build a sustainable business, that won't make them one.

I said 'Not being a major OEM' is one of their USP.