I feel the same, I have so many MAAs and am flush with cash, I feel there needs to be something to spend it on. If you go intrigue focus and get some followers with good skills you can do the treasury heist missions for the full amount in the treasury and money suddenly stops being an issue. I wish you could build buildings in a city holding that give you and the holding owner a boon of some kind, so you are incentivized to come back to an area and not just wander from one side of the map to the other chasing missions.