I'd say it's because way back when, Meghan and Harry brushed off the potential loss of titles and financial support as a bluff by Charles and the Queen. It would take time to rescind the titles and Harry could draw on his inheritance from Diana and the upfront payments from Spotify and Netflix if they needed immediate money. They likely thought they had time to force the Queen and Charles to apologize and give them the half-in/half-out deal they wanted. They also likely believed their own hype that they were a billion dollar brand, all on their own.
Instead, years have passed, no apology came because they made so many inaccurate statements and "recollections vary". They got no half-in/half-out deal. They have not been paid big dollars to hit the speaking circuit. Meghan's children's literature career consisted of one poorly received book. They also have had to deal with many PR screw ups (the cemetery pap walk, Ellen appearance, Uvalde appearance, skipping Prince Philip's memorial service, skipping visiting the Queen this summer, etc.) and the public perception, certainly in the UK and in other countries, that they made Prince Philip and the Queen's final years unhappy. So, they are in a weaker position now, especially with both Spotify and Netflix expecting a concrete return on their investments in the next few months and that billion dollars not magically materializing.