I think OP's title itself answers the question — they're wealthy, and most if not all things that he could really want in the world is a transaction away. "Constraints" are key to finding purpose and direction. There can be a right/optimal set of constraints, but when there seems to be none, any is better. Constraints forbid us from being able to have something in life (things or experiences) that we also want. When we can satisfy any want, it doesn't feel like the wants matter anymore. The very reason the want existed in the first place was because it was not something that was possible at the time.
I'd advise OP to strategize smartly, given they have enough money to last a simple and full life, save, invest, donate, and keep the transactions small; ie. not investing or donating all or a majority of wealth into one thing, instead of a little bit here and a little bit there, every now and then, gradually and slowly.
Taking it slower itself is a form of constraint. And together with keeping relationships and connections, minimizing the noise in life, and making it simpler towards enjoying the truer pleasures of their life, they can grow richer and live more luxuriously, not just in terms of wealth, but also in a safer, more secure and a cozier human experience.