OK, a few points.
1. Archie, as a great-grandchild and not in the direct line to the Throne, is not automatically entitled to the title of Prince or the address, Royal Highness. As heir to the Duke of Sussex he is entitled to the courtesy title of Earl of Dumbarton, which his parents elected not to use.
2. The Royalty and Specialist Protection Branch (RaSP) is part of the Protection Command of the Specialist Operations directorate of the Metropolitan Police. Part of thier role is to provide close protection for government miisters, visiting Heads of State and designated members of the Royal Family. The RaSP is funded by the Treasury and does not take orders from the Royal Family but through standard police channels. The Queen may request protection for members of the family, but the decision rests with the Metropolitan Poloce Commissioner and the feasibility with budgets. Thus only key indifivuals receive close protection, though the Special Escort Groups and armed security for residences have a wider remit. The Sussexes request that Archie live as a private citizen is what renders him ineligible for protection.
3. Money. As the couple no longer perform Royal duties, they are no longer paid from the Civil List -government funding given to support the necessary staff and expenses involved in official events. As they retain the titles of Duke and Duchess of Sussex, they would be theoretically entitled to any revenues from that Duchy but I don't believe there are any. Thus financial futting off wouldmean no more than the cessation of allowances made , either from the Duchy of Cornwall, held by Prince Charles, or the Queens' personal fortune. So they stopped his pocket money. Boo fucking hoo. You're a grown man, get a job!
4. Racism. If you put a gun to my head, I'd have to say it was either one of Prince Philips' 'jokes' or 'gaffes', or a genuine question from Prince Andrew, who is as thick as two short planks even by the standards of that family.
In conclusion, the whole mess revolves around three things. Harry's lifelong desire to get the hell out. The Abdication. Kate, who is a clever and strong-willed woman intent on guiding her nice-but-dim husband and the Monarchy altogether in a new, socially-responsible, direction. The presence of a loud, spoiled, entitled, neurotic and needy prima donna like Meghan (Harry, like many men, married a woman who is far too much like his mother) would be a hindrance to Kates' agenda.