Me-rail: my dad died needlessly because he had such severe death anxiety, that it made him scared of medical treatment because he was so frightened of hearing something negative. Minor niggles became lethal catastrophes. He did not understand that he was harming and killing himself and couldn't process that he would actually avoid hospitals more effectively, if only he would do the initial treatments/investigations. He would lie to the doctors so they would say what he wanted to hear. He hid his medical papers from us. He would not admit to anyone the extent of his health issues. He chose which medication (very important medications) to have or to not have, and how much. He believed the body had a huge healing capacity with the correct lifestyle and diet. He would not believe or accept that some things are irreversible. Such as his self-inflicted kidney failure and subsequent heart attack. We couldn't talk to him about it because he would become too distressed (that is simplifying it - a lot). We couldn't get doctors or nurses to believe he lacked capacity and truly didn't understand that he was killing himself. We couldn't get social services involved because he would have known exactly what to say to get them off his back (also, he hated them and would have never have forgiven us and it would have been futile anyway).
I have a lot of empathy for Hollie because I have lived experience of dealing with a delusional person. Just like Hollie, my dad wasn't completely delusional, because if he was, he wouldn't have known what information to selectively share or hide, and he wouldn't have known what to say to doctors or doubters. Delusional beliefs are weird because they are genuine and strongly held, yet they are somewhat partial. Also like Hollie, my dad in some ways wasn't too bright, and also didn't have much medical or scientific knowledge. Another similarity was that hearing the right things was of the utmost importance to him. It didn't matter that the doctors telling him he was absolutely fine was based on his lies - the most important thing was that they said it. I see similarities with Hollie in that she is cultivating her followers to say things that are comforting to her, so that at least some of the time, she can retreat into a comforting fantasy that miracles exist and Archie might wake up. Even though they say these things as a result of her manipulation. There is also a similarity in that she is saying what needs to be said in court (and on some level, may logically accept it) just like my dad would say what was necessary to doctors, yet as soon as she is away she says what she really feels.
My dad had severe mental health problems, and I suspect Hollie does too. People would rally round my dad because his distress was just so extreme that you would rather prop him up emotionally with whatever he needed than let him face his genuine turmoil. He was not capable of learning or changing so there was no point in denying him. I get the sense that Archie's other family members are rallying like this for Hollie's sake. Even if they personally would rather let him go, Hollie being in Fight Mode is what is sustaining her right now, along with clinging to Archies warm body. So they are joining her because that's what she needs emotionally. Now Archie is essentially gone, their main focus is on protecting Hollie. I also suspect that her family have long since accepted that Hollie is not capable of changing or learning.