This does touch home to me as I am the matriarch of a large family. I have 3 sons and their wives, 3 daughters and their husbands and 19 grandchildren. I can think of many moments I would like to take back and have a do over but I certainly hope none of them have the feelings that Prince Harry does. Of course, we aren't royals, but we dealt with sibling rivalry, etc. etc.
You're assuming that Harry has certain feelings without reading the book. If you want to believe the tabloids and headlines and get upset about them, then that's on you. You could just read the book and realize that many reports are misleading and selective. If you think that the book is just a hatchet job on the queen and on Charles, you are wrong.
Harry seems to have loved and respected Elizabeth as grandmother, queen, and commander. He is not critical of her and anything negative would be a question of judgment for the reader.
From reading the book, I do get a strong sense of affection between Charles and Harry. Harry's anger seems to mostly be related to the tabloids and security (and relatedly to Camilla). I already had watched the Netflix show and knew how Harry felt about those issues with Charles. Aside from those issues, though, I think Charles actually came across better in the book than I expected him to. Harry does write about Charles walking Meghan down the aisle. There are other smaller moments, too. And it is these smaller moments, at least for most of the book, that do the most to show the love between Charles and Harry, even if the book does also indicate that Charles was not always a very present and engaged father and that Camilla may have been a bigger priority.
Harry did seem to spend a lot of time not being around his family (including both Charles and William), which is not unusual for that family, but sad nevertheless, especially as a kid after his mother died. Charles may not have a lot of empathy in some situations, but that doesn't mean that Charles wasn't understanding and kind at other times, even when Harry was screwing up, and Harry does discuss some of those times.
I don't get the sense that William and Kate spent much time with Harry even before Harry met Meghan. Although the book definitely includes conflicts (including physical ones) between William and Harry, it is much more complex than that. Harry writes about his uncle being upset about Harry and William having to publicly march behind Diana's coffin and the proposal someone made that only William march. The palace said both had to march, but Harry says he never would have wanted William to have to deal with that alone. Harry writes about being excited when he became an uncle and offended when someone assumes he would not be excited (because it sends him further down the line of succession).
But, if you want to assume what Harry's feelings are and be upset or angry about it or not learn about any of the flaws some of his family members have, that's your choice.