Indeed, big house, fast car and lobbying to make even more money...

I'd like to point out it's titled "what to do?" while it was actually an answer to "what to buy?" so the problem is more about the implied confusion between buying, doing and being.

So, buy a big house if you want but maybe also some free time to work on yourself so that you have a better grasp of who you really are because if your whole life revolves around making and spending money it sure as hell can be depressing.

With very rare exceptions that'd be a level or two up on the Maslow's pyramid from where this list is.

At elite levels, yes, sure, and then it’s still about ego.

It doesn’t take that much wealth to buy some time, to network, and then focus one’s attention on local charity. Often the way to build resilience and have impact in a community is to demonstrate local leadership, so that everyone chips in. That is the sort of thing one can afford easily when one’s a millionaire (though it’s not necessary to be rich to do it).