Maintenance? Imagine having to move out your house for a few days to weeks while work work is done.
BTW, I really enjoyed living aboard our boat right in the center of downtown and right on the river. But our kid was getting bigger and the novelty of not having the space to be a kid was wearing them down.
Empirically, it is cheaper to live aboard a boat but you give up a lot of quality of life conveniences to make it happen. You could save a lot more money by renting a small <500ft^2 apartment. Effectively that is what your doing anyway.