Gramsci How is it in any way GrapheneOS's fault? Also, not clear to me you understand the nature of the project. There is limited resources with the need to constantly triage in order to keep things on track. It's not like the team is maliciously putting this on the backburner as half your posts seem to insinuate.
If you really have read my prior posts, you'd know the answer to your own question and that plenty of other people agree with me. I also have not "insinuated" anything, I have been very direct in my statements about why I think Graphene should take more responsibility for the problems with RCS.
GrapheneOS changes Android and the way Google Play Services and default apps like Google Messages work, in order to create more security. They do a ton of work to create a compatibility layer so Play Services will work as a regual sandboxed app. This is great. But it turns out it breaks the way Google Messages on Android is supposed to work, with special system level privileges. As a consequence of this, anyone who enabled RCS while it was working is now stuck in a situation where, with RCS now not working on Graphene without the special privileges, their group messages break. These users cannot simply disable RCS, because group messages will not fall back to MMS. This means that Graphene users now have any exisiting group messages broken with carrier based messaging. The only solution is either to use hacky workarounds with old vesions of Messages that have to be repeated every 36 hours and could stop working at any time; get everyone in every group message to delete the thread on their phones and only after that create a new one (which is practically impossible, especially for large group messages); or to go back to stock Android, where Google Messages and RCS work as they were designed to work.
This situation is unique to Graphene, because of the way it's security is designed. Graphene's security design effectively breaks carrier based messaging, for anyone who enabled RCS in Google Messages and then had the way RCS works later change in a manner Graphene does not allow. Other people on stock Android may have problems with RCS, but not this problem. So this is a bug that Graphene causes with carrier based messaging.
If this were just of question of getting RCS to work, because people would like to use it, but they could freely enable and disable it with no consequences, it would not be a bug and it would not be a problem. But because a very large swath of users who were using RCS when it worked fine are now stuck with group messages broken on carrier based messaging (about as basic an element of mobile OS functionality as you can get) this is a serious bug.
Meanwhile, the Graphene devs have increasingly downplayed the problem. First they said addressing it was a priority. Then when it turned out the easy fix did not solve the problem, they said, well it "only" affects people on T-Mobile. Then when AT&T made the same changes they said, well, it "only" affects people on T-Mobile and AT&T, ignoring the fact that this covers two thirds of the carriers in the one country where every major carrier has enabled RCS and where RCS is most widely adopted. Meanwhile, the devs insist on Github that resolving the issue is a feature request and not a bug. Devs and mods have also unhelpfully said they do not recommend people using old versions of Google Messages, as if this is what people want to be doing and have any good other options. Many people have also requested the devs allow a temporary workaround where users can choose to enable the special privileges for Messages, as can be done in Graphene with Android Auto, but the response has been, no, that's not our way, placing purity over practical solutions for Graphene users stuck with broken carrier based messaging and no solution.
What's more, these problems will probably only get worse, as more carriers update their systems and then RCS stops working for more people on Graphene, leaving them trapped with broken group messages on carrier based messaging and no solution. Letting this problem fester is not going to serve Graphene users well. At a minimum, there ought to be a big red banner in the install instructions for Graphene telling people that under no circumstances should they ever enable RCS in Google Messages, because it is not really compatible with Graphene and is likely to break carrier based messaging in the future, forcing them to go back to stock Android.
At the end of the day, Google and Apple and the carriers have all contributed to this problem. But there is a specific way in which, as I explain, it is unique to Graphene and for better or worse only the Graphene devs can solve it.