I hate the aggressive RCS rollout.
The rollout of RCS messaging is more or less the death of custom roms on Android phones. Since the security checks for RCS do not pass on custom roms without hacks in some cases, you either have to be okay with only partaking in SMS conversations with individual people with no group MMS threads, or convince everyone else in your life to allow SMS chats on their phones via the message settings menu. My family is all on iPhones, so of course when they got opted in RCS, my group MMS conversations with them just broke, and it took a couple days for me to figure out why because I'm a massive retard I guess.
When it comes to LineageOS and other custom roms, the proposed solution to the RCS rollout is to use modules in root, which I do not believe is a real solution since there is no way that's permanent, and all it takes is a single update to break compatibility, and you may not even be aware that happens. As for GrapheneOS, all we got is a forum thread that is multiple years old with no actual update to make it work reliably, and temporary fixes that only get it working until an update comes out.
As for the solution being "just use Signal", okay, good luck getting your normie friends and family members to sign up for Signal and use that for texting just for your benefit.
I understand that RCS is inherently more secure than SMS, but I don't think the ability to make texting act more like iMessage is worth having such restrictions on your device.