I know it's not a lot for the likes of Samsung, but FairPhone, for instance, sold 100k units in 2023.
So if FairPhone made their hardware work with GrapheneOS, they would possible double their marketshare. Also for a major manufacturer like Samsung or Huawei, it feels like it shouldn't be too hard to meet the GrapheneOS requirements, and that would immediately get them those customers that want GrapheneOS (especially given that Google has been seen less reliable recently).
Why is it that Android manufacturers just don't care? Is it too much work for a market of hundreds of thousands of users (and growing)?
[1]: https://discuss.grapheneos.org/d/1137-market-share/16