While many banks offer no fee accounts nowadays, the majority of banks still charge some kind of fee to do business with them. In a lot of cases too, when it comes to paying the bill a lot of people still bring the bills to the bank and pay each one individually. What I noticed was that for many people their banks charge them a transaction fee for doing things like this. So unless you are under some kind of plan that gives you X amount of free transactions, you could get deducted for paying too many bills in any given month.
For myself, I usually only need to do one bill transaction from the bank a month when it comes to expenses. For example, for like the phone or cable bill I suppose many would just pay each one individually directly from their bank making it two transactions. However, I tend to use the credit card to pay the bills and so at the end of the month I just need to do one transaction which is to fully pay off the credit card balance.
I find this to be good from a general organization point of view too as you can condense all of your reports easier. Even for accounts that have no transactions fees I still do the same.