Meghan's acting career (such as it was) is over, and while she may get residuals from
Suits, that's not going to be anywhere near enough to cover their expenses. She was well-paid while on the show, but still had to pay her agent and manager, and lived an expensive lifestyle. She didn't own a home of her own, and complained about trouble with her finances before marrying Harry. So there's nothing there. She did get a deal to write a children's book (called
The Bench), but it was a flop, so again, there's no steady, reliable stream of future income there.
They get no money from the Royal Family. Diana left £13 million to her sons when she died, and Harry has said that his share (we can assume half, or £6.5 million) financed their "escape." The Queen Mum may have left him additional funds upon her death in 2002, but we have no way of knowing how much. And Charles himself gave them a significant amount of his own personal money as part of their Megxit agreement, but again, we don't know how much (my guess is around £5 million, because that's what the Royal household spent on them in the year before Megxit; if it was more than £10 million, I'd be shocked).
That sounds like a lot of money, but keep in mind, they have
enormous overhead, and they now have to cover all of those costs themselves. Meghan bitched about Frogmore Cottage, but she didn't have to fork over the cash to live there or maintain it. Now they've got a $9.5 million mortgage on a $14.7 million house* (9 bedrooms, 16 baths, 7 mostly-landscaped acres), along with all the property taxes, insurance, utilities, staffing, and maintenance costs that go with that. Those expenses could
easily run them $4 million a year. Plus, they need to hire their own security, both at home and when traveling, which, for 24/7 protection, is going to be in the low millions per year (and will likely go up now that Harry has
stupidly bragged about killing 25 members of the Taliban).
Then there's the costs of living Dat Sussex Royal Lyfe. The vehicles, clothing, furnishing and decorating the house, kids' schools, nannies, travel and lodging costs, personal assistants, therapy bills, concierge medicine, agents and business managers, attorneys, all of the costs involved in keeping Meghan looking good (hair, makeup, Botox, dermatologist, aestheticians, etc.), Harry's polo playing, countless incidental expenditures—it goes on and on and fucking
on, and nothing is done on the cheap.
One thing they don't have is a private jet, but it's not for environmental reasons; it's because they can't fucking afford it. They really, honestly, just cannot. You're looking at $4-5 million/year in costs, and that doesn't even count the cost of the plane itself. The plane that flew them to Vancouver when they escaped belonged to Tyler Perry (who was convinced to take pity on a poor, oppressed sistah fleeing vicious racism), and ever since then Meg's been hitting up their much-wealthier Montecito "friends" for flights on their planes. I can't recall where I heard it (maybe from Lady Colin Campbell, who is a fucking riot), but apparently she's wearing their patience thin.
*Oh! And the house they're paying that big mortgage on? It was recently identified by Santa Barbara County as being smack in the middle of a mudslide zone. After the fires in 2017 burned the shit out of the surrounding mountains, leaving them without adequate vegetation to hold the soil in place during the rainy season, the danger of land-/mudslides has increased tremendously. So if, for some reason, they had to sell that house, they would have a very hard time of it, and probably have to sell it at a loss. Their property taxes might go down because of that, but their insurance costs will be astronomical.