Thoughts
I think it's going to be funny if atheists re-invent church but without the tithing part.
Christianity is radical in a lot of ways, and some of those things have direct parallels in secular tradition, or I predict that they will in the future.
Like traditionally many holidays in the US have been religious, but atheists don't (generally) dislike holidays. And so I think that if our culture continues becoming more secular, we will end up with more secular holidays. (Pride and Juneteeth come to mind as relatively new widely recognized secular holidays.)
I hope and I suspect that in the future, in the same way, atheists will "re-invent church." Not in the sense of "pastor" and a "sermon" (although it is done; if you google atheist church). But in the sense of a regular meeting of community members; there are any number of organizations or clubs or groups could expand the fill that role. (Although I think it would be important to have it be a larger group of people than just a group of friends.)
But I anticipate that it would be easy to miss the aspect of church where, at least some part of, the congregation tithes. 10% is really an unintuitively large amount of money.