Big ego’s involved here (much as I like Harry and I don’t mean just his ego).
Clearly they thought they could support their lifestyle airing dirty laundry, doing show business and endorsing charities. But that’s either not materialised or isn’t lucrative enough. Or they've messed it up!
Talk of Spare volumes 2 and 3 has hone quiet. I’m sure the plan was for 2 more books.
Harry & Meghan didn’t get what they wanted, had a tantrum and left home. 5 years later have realised it’s not going to pay the bills and are running back to daddy. A tale as old as time.
Also, I expect he felt a lot of pressure to write Spare. Publishers must’ve been rubbing their hands thinking of the miney involved in the sale of that book.