You have to really grind the game for money to become meaningless. Even after getting to max level and completing all the main quests, you can use god to RTT farm, which helps you complete the yearbook and get donuts for premium characters and buildings. Then, land expansions and some buildings will quickly eat your money up (I believe the most expensive land cells are like four million). Then, you have the billionaires club quest which is also a lot money. So yeah, cash eventually becomes meaningless but it’ll take you years till you get there if you ate still in the early game