The person called low maintenance may have learned not to report what maintaining the relationship costs them.

Low maintenance often means someone stopped reporting the cost. They still need things; they have simply learned that mentioning them is unwelcome, so the maintenance moved out of sight and got carried privately. The label describes their silence rather than their needs.

If someone in your life is described this way, including by themselves, assume there is an account you are not seeing and ask specifically rather than generally. And if you are the low-maintenance one, notice how much you are absorbing. Being easy to be around is a genuine gift, and it should not require you to pretend you cost nothing.